UPDATE:
OK, we've reverted to 10.0.1, since it doesn't have the lagginess. 10.0.2 seems to hose performance of the OS, too, even when not running ArcPad. Boo!!!!! We had one sample uno SB unit that we bought months before the 10 production units. Finally realized the only difference between the one that worked great, and the 10 bricks, was the ArcPad version!