The T-Mobile Shadow is one of the few Windows Mobile devices on the market that makes use of the slider form factor. The design allows the Shadow to use a massive 2.6" main display while still having enough room left over for a full control cluster and a 20 key alphanumeric keypad. The Shadow isn't small, at 104mm x 52mm x 16mm (4.1" x 2.0" x .6"), but it is pretty light for its size: only 108g (3.8oz).
The display itself is a 65k color unit with QVGA (240x320 pixel) resolution. There is no brightness control, automatic or otherwise, on the Shadow, but it does have a power saving dim mode that it enters after a user configured number of seconds. After a second user configurable timeout, the display turns off completely. When the display is on, text is crisp and bright and very easy to read.
Beneath the display is the main control cluster. The controls include a pair of softkeys, a pair of larger home and back function keys, the red and green call keys, and the dual-mode d-pad that can also be rotated to act like a scroll wheel. The d-pad works very well for normal up/down/left/right navigation, and is passable for scrolling. My impression is that the scroll wheel works fine physically, but that the software support in certain sections of the phone is not calibrated well. Either way, it is very nice to have in certain situations. I also like that the center of the d-pad glows a soft green color for a short time when a new message arrives. A pair of small LEDs near the earpiece of the phone provides long term status information for new messages and charging.
The last major attraction on the Shadow is its 20 key hybrid keypad/keyboard. Looking very much like the SureType keyboard RIM developed for the Pearl 8100, the 20 keypad on the Shadow improves upon the accuracy of predictive systems like T9 without requiring the 50+ keys found on a traditional QWERTY keyboard. It has some issues, which I will talk about later, but in general it works very well for light messaging. The keys themselves are very large and stable, and offer nice, consistent tactile feedback. There is a bit of a problem with the backlight, though. The backlight for the keypad and the softkeys will sometimes turn off and not turn back on even if the d-pad is clicked or scrolled. This can be a real problem when using the device in the dark, as you have to hit a keypad button (that you can't really see) in order to get the backlight to turn back on.
The rest of the physical design of the Shadow is very nice, as well. While the gold-green color scheme of our review unit might not suit everybody, few will take issue with the build quality of the device or the nice soft-touch paint used on its back cover. Other controls on the Shadow include a volume rocker, a camera shutter button, and a user configurable shortcut key, which I used for messaging and voice dialing. A microSD memory card slot and the miniUSB power/data/headset port are also easily accessible on the left side of the phone, even though the attached covers seem to be a bit stubborn during removal. The 2 megapixel camera lens and speaker grille for the ringtones are located on the back of the device.
Apart from the sometimes slow scroll wheel response, I truly love the physical design of the Shadow. It is simple, comfortable to hold and use, and has elegant lines and curves.