from what ive seen/felt...the MX510 is feeling pretty good. Im not too sure about the Intellimouse product line though...because a couple friends of mine had it and it just "glitched" out or "spun" out every now and then. It pissed them off when they played counterstrike..quite amusing it was probably because they didn't have the righ drivers though...
personally myself....i use a ballmouse.. a "Compaq" the one that came with my computer
mx1000 66 bucks or so
razer diamondback 50 bucks
mx510 forgot the price
supposively an mx518 wired mouse is coming out to compete with the razer diamondback
Id avoid the MX1000 for gaming until Logitech fixes something with their damn drivers:
1. Randomly (and not just once in a while, almost persistently), buttons dont get "relased" when you lift yer finger (you can see how this can be a bad thing say playing UT2K4 in a small corridor with a rocket launcher that wont stop shooting)
2. Randomly (less often than #1), the damn thing wont register a mous click when you tap the button (making headshots a really hard thing to do cuz you dont know if the gun will shoot or not)
3. Randomly other buttons get depressed without you pressing them..... like the application selector....
4. The left/right scroll thing is too sensitive (thus making it hard to utilize the wheel as a button)
I plan on buying a logitech MX510. From what I been told it a great mouse. I curently using a microsoft opticle. The microsoft was bad without a mouse pad. It would spin out of control at random. Since I got a good mouse pad it been fine but I still think am going to upgrade to a mx510.