I have only two real problems with uControl:

It it never "sticks" on. I think its for some kind of security thing so it wont kill your computer, but I have to re-enable it every time I reboot. Thank goodness this isn't OS 9...

With the arival of my 17" PB, the left and right sides of the trackpad appear to be "dead" to uControl. I guess it just doesn't look there, requiring a tab bit more effort to scroll with one hand.