I've been using the new MX-1000 cause I was extremely dissapointed with Microsoft's latest explorer mouse. I used to be a die-hard user, untill they took the clicky-ness out of the scroll wheel. Trying to use your scroll wheel in games for weapon selecting or anything is just about impossible. If you scroll it slow, it wont change. If you scroll it fast, it zooms through the entire list. wierd.
Anyways, I wanted to go wireless too, and it's been a good mouse functionality wise, it's just been a little squirrely under windows. Like it's a bit TOO sensitive.
If I could get away without using Setpoint with this mouse, I would, but I need Setpoint in order to run Logigamer, which allows me to customize every single button on the mouse to do something different than what Setpoint allows. it's necessary for my keyboard-mouse combo in Freespace.