The 8830 measures 114mm x 66mm x 15mm (4.5" x 2.6" x .6") in size, which is 7mm longer and 16mm wider than the Pearl 8100. At 134g (4.7oz), though, it is 43g (1.5oz) heavier than the Pearl. The end result is a device that is a bit less pocketable, but one that offers a QWERTY keyboard and a larger, higher resolution display. In fact, I was quite pleased with the display on the 8830. It offers QVGA (320x240) pixel resolution in a landscape orientation and has good color saturation and brightness, even outdoors. The automatic brightness adjustment mode keeps the display readable while conserving battery power. The display measures about 2.4" across the diagonal, which is reasonable for a device of this size.
In terms of tactile feel, the 8830's keyboard is very good. The physical design is also good, with one exception that I will get to shortly. Upon initially seeing that the period (full stop) key required an ALT shift to access, I admit that I was surprised. But RIM thought through this more than I had initially given it credit for: entering two spaces in a row will automatically covert the first space to a period, making the period key needed only for the occasional number. Capital letters can be entered using the traditional shift keys, but are more conveniently entered by long pressing the key. The 8830's AutoText function can automatically change words like "dont" and "cant" to "don't" and "can't", saving the user from a lot of the keyboard gymnastics required by most mobile devices.
There is a major problem with the keyboard, though: the keys are very hard to read - even in ideal circumstances. The issue is the backlight, which is blue (always a bad choice). Uneven lights under the clear number and letter shaped windows on the keys mean that depending on the viewing angle, different parts of the letters and numbers on the keys are lit. It seems that 8830 users will simply have to just get used to typing blind. By comparison, the keyboard on the 8800 for T-Mobile was very easy to read in both bright and dim lighting conditions.
Navigation on the 8830 is handled by the trackball. The trackball makes navigating large menus or emails a snap, and also obviates the need for a separate scroll-wheel. Pressing the trackball will act the same way as the center button would on a typical d-pad. It works very well.
The rest of the controls and features are found on the sides and back of the 8830. The volume buttons are on the right edge, the headphone jack and mini-USB power port are on the left, as is the voice dial button (which can be reconfigured). A power button and a triple-function mute/music player/standby mode button are found on top. The microSD memory card slot is located under the rear cover, but unimpeded by the battery, so a restart is not necessary when swapping cards. Lastly, the 8830 ships with a leather case for your belt. A magnet in the case automatically puts the phone in standby mode when inserted, and wakes it when removed.