The feature I miss the most from my other keyboards:
Next/Previous media track buttons
ANY programable button (to launch Calculator.exe) - fucking MUST!
Well, after about 2 weeks of typing on this board, I can safely say that my accuracy and speed has improved over the MS Natural board I used. It's nice n' heavy, the wrist rest extends, the keys are fairly quiet with tactile sensation, and ALL the keys are where they oughta be.
Unfortunately, the volume keys don't seem to work while in Sensaura (game mode) on my M-Audio Revolution sound card.