The Duo (also known as the C810) is a dual-slider handset that sports both a traditional numeric keypad and a full QWERTY keyboard. In order to accomplish this, a few compromises had to be made. For one, at 102mm x 50mm x 22mm (4.0" x 2.0" x .9"), the Duo is not a particularly thin handset. Its 128g (4.5oz) weight isn't going to set any records either. But all in all, Pantech did a fairly good job of keeping the size and weight of the device under control, which keeps the Duo looking, for the most part, like any other slider smartphone.
The most interesting part of the Duo's physical design, as well as the part that involved the most compromises, is the slide out QWERTY keyboard. In order to keep the Duo's overall thickness in check, Pantech had to make sure that the QWERTY keyboard was very thin. This led them to use fairly soft rubber keys that don't provide very consistent tactile response. The space bar is particularly bad in this regard: pressing on the left or right edge of the key feels fine, but the key becomes very stiff feeling if it is pressed dead center. This lack of consistency, which is present on most of the keys (to a lesser extent), makes it hard for users to quickly and confidently enter text on the keyboard. One nice point about the keyboard is that numbers and symbols can be entered with a simple long press, removing the typically required Fn key shift from the input equation. The last keyboard related issue is the lack of a spring in the keyboard's slider mechanism. There is no snap open or snap close, which lowers the overall sense of quality the Duo otherwise exhibits.
The numeric keypad suffers no such problems. It is as good as, or better, than the keypad found on most other slider handsets on the market. The keys have a good feel to them, and the slider mechanism is spring loaded so that it confidently snaps closed and open. It is so good, in fact, that it just highlights the QWERTY keyboard's lacking in this regard. The rest of the Duo's controls are located directly below the main 262k color, QVGA (240x320 pixel) display, which is clear and bright, but prone to internal dust accumulation, as seen in our screen shots. The d-pad is a bit small, but works adequately well. The left and right softkeys, the home and back buttons and the red and green call keys also perform well. Under the d-pad sits a button marked with camera flash and lock symbols. This button, in spite of the iconography, brings up the Windows Mobile Quick List, which provides quick access to the wireless manager, the profiles, and a power-off option.The body of the Duo is covered in a dark gray metallic color scheme that seems reasonably resistant to scratching. A decent volume rocker switch sits on the left edge of the phone, directly opposite the Duo's record and camera buttons that sit on the right edge. These two buttons are poorly positioned, being too close to each other and too well lined up with the volume controls. It is simply too easy to trigger the volume when gripping the phone to press the record or camera buttons. The opposite is also true. A device like this really doesn't need a dedicated camera key, though the record button is useful for launching the voice dialing app. The back of the phone is home to the 1.3 megapixel camera's lens and self-portrait mirror, the speaker grille and the snap on battery. The slight bulge of the battery prevents the speaker from being blocked when it sits on a desk. The bottom of the device is where Pantech placed its proprietary charger/headset port (miniUSB would have been much more convenient). At least the supplied USB cable can charge the phone. The microSD memory card slot is cleverly located behind the display that is exposed when the keypad slider is extended.
The overall design of the Pantech Duo is decent. If you look at it primarily as a regular slider form factor smartphone, one that just happens to have a QWERTY keyboard to help ease the occasional messaging need, then the design works. If your phone needs require more frequent and heavy text entry, then the keyboard's feel is probably going to leave you wanting for more. The Pantech C810 Duo manages basic phone related tasks quite well. The quad-band GSM/EDGE, dual-band UMTS/HSDPA (850/1900MHz) support in the Duo means that it fully supports AT&T's 3G network as well as basically any GSM network in the world. In my personal usage, the Duo's internal antenna performed pretty well. Most of the time I was able to get a 3G connection from my home, and when I couldn't, the GSM connection was rock solid. In our battery tests, the Duo managed 4.5 of talk time. Call quality was generally good, although the audio during speakerphone use was only of average quality.
As is the case with all Windows Mobile 6 Standard (smartphone) devices, the contacts system on the Pantech Duo is well organized and very complete. Nearly any conceivable piece of information can be stored in a contact record, from typical things like phone numbers, custom ringtones, and a photo, to more obscure details like "Government ID" and "Manager". The contact editor could be organized better for dealing with all of those options, but at least the raw capability is there. Contact searching is simple: you just start typing a name with the keypad or keyboard and the contacts list appears, drilling down further with each key press. If using the keyboard, a space can be added to the entered search text to make the system match both names at the same time: "J D" would quickly find John Doe, for example.
The profiles system on WM6 Standard devices is relatively simple, but generally adequate. While it is not possible to assign separate ringtones to the different profiles (such as Normal and Meeting), each profile can be configured in fine detail as to how it will interact with the user when it comes to phone calls, received messages, alarms, and other notices. Each individual type of ring/alarm/notice can be configured in a profile in various combinations of different vibration types and sound volumes. There is even an automatic profile mode that will switch the phone into vibrate mode for any appointments in your calendar, and then switch back when they are over. The profiles can most easily be accessed from the Quick List, which is called up with the dedicated key located below the Duo's d-pad.
WM6 has a flexible speed dial system that lets speed dial numbers be assigned not only to contacts (in the contact viewer), but also to applications. Applications are linked to a speed dial from the main menu's right softkey 'menu' function. Once assigned for either a contact or application, a speed dial can be accessed by long-pressing the associated key on the keypad. An equally useful function is the speaker independent voice dialing and command system that is on the Duo. Not only can the voice command system be used to effortlessly dial contacts, but it can even announce callers, read received email or text messages aloud, or be used to cue up songs in Windows Media Player. It is a fantastic application.
The Pantech Duo supports traditional SMS and MMS messaging as well as email and IM. The included IM app integrates MSN, AIM, and Yahoo! Messengers into one central location that is quite easy to use. The email support on the Duo is also very good, thanks to the inclusion of Microsoft's Exchange Activesync system that can deliver push email as well as synchronize appointments, contacts, and tasks over the air. When the phone is paired with an Exchange 2007 server, users can even search for messages that are stored on the server, but not the phone, which can be tremendously handy. The solid messaging app on the Duo also supports regular IMAP and POP based email accounts, with all accounts of all types, except for IM, being handled by the main messaging application. Users can easily switch from one account to the next by pressing left or right on the d-pad. The Duo can also be synchronized with desktop apps like Outlook by using Bluetooth or a USB cable. AT&T and Pantech have added a number of other applications to the Duo. The ClearVue PDF viewer is available, as are trial versions of My-Cast Weather, MobiTV, and MySpace Mobile. The included MusicID application lets users identify music that is playing on the radio or another nearby audio source. It is pretty cool, if a bit slow at making the actual identification. AT&T also includes a number of links to its own video and music services, and the Duo supports 3rd party Java applications as well.
Between its Windows Media Player application and its included 3.5mm headset adapter and Bluetooth stereo support, the Pantech Duo is fairly capable of acting as an MP3 player. The Windows Media Player might be awkward to use at times, especially when it comes to creating playlists on the phone, but it plays the actual music tracks quite well and synchronizes easily with a desktop computer via the supplied USB cable. The ability of the Voice Command application to start the music playing with voice commands is especially handy when the Duo is paired up with stereo Bluetooth headphones, such as the Motorola S9 headphones that we tested it with.
One of the areas where the Pantech Duo comes up short is its camera. For such an otherwise well equipped handset as the Duo, it just seems strange to place a lowly 1.3 megapixel camera on-board. I don't mean lowly simply because it has a 1.3 megapixel resolution, I mean lowly because the photos it takes are largely useless to anybody I can imagine. The camera can also record video, but again the quality is so poor as to not matter.
The Pantech Duo has about 56MB of on-board storage, of which roughly 48MB is available to the user. There is roughly 55MB of application RAM in the Duo, 34MB or so of that being available after a restart. Storage can be augmented by inserting a microSD card into the Duo's card slot, but no card is included in the retail package. User Interface
As a Windows Mobile 6 Standard device, the Pantech Duo's user interface should be quite familiar to anybody who has used any other WM6 or WM5 device in the past. In this particular case, Pantech did not make a lot of customizations to the stock system, which is not necessarily a bad thing. As a Windows Mobile 6 Standard (as opposed to Professional) device, the Pantech Duo has no touchscreen. All user interactions are handled by the keys and d-pad controller. The main screen on the device is called the home screen. The home screen can be configured to use a number of different layouts, including a few AT&T specific layouts. Most of these layouts provide a decent amount of basic information at a glance, such as the current day's appointments and counts of any unread messages or missed calls. The color schemes used by the phone in general can be user configured as well.
The main menu of a WM6 device is accessed by pressing the left softkey, which brings up the Start menu. The menu on the Duo is arranged in an icon grid configuration with no option for switching it to the commonly-featured list view. The icons in the start menu are arranged somewhat haphazardly and can not be reordered by the user without resorting to the types of minor hacks that most users would never attempt. As is the case in most all parts of the WM6 user interface, the right softkey brings up a pop-up list of additional options, the left is associated with the most common task for the given screen or currently highlighted item, and the d-pad's center button acts as the select key to activate the currently selected program or item.
From anywhere in the system, users can press the dedicated home key to get back to the home screen (the red call end key services the same function). The dedicated back key can be used during navigation to move back a screen or two without having to start over again from the home screen. While there are a few situations where the back key will not work as expected, the situation has been much improved over what Windows Mobile 5 users experienced.
While I don't find the device to be particularly sluggish, Pantech saw fit to include a 'turbo' mode in the Duo's settings that appears to speed up the processor a bit. This does, of course, increase the amount of strain the Duo puts on its battery, so be forewarned. In general I like the Windows Mobile 6 OS and user interface, but it does feel a bit less organized than usual on the Duo. This means that while it is very powerful in terms of its raw capabilities, the Duo is not exactly a device that novices will take to right away.
