This is one of the few products Microsoft has made that I actually like and recommend. I don't have the Explorer; I have the Intellimouse Optical, which is similar, but slightly smaller, ambidextrous and has one less button.

It tracks flawlessly on pretty much any surface; I still find myself using a normal cloth mousepad, though, because it has just the right coefficient of friction for moving the mouse comfortably]. It has also improved my Quake 3 game considerably, despite people saying it can't track fast enough. It tracks more than fast enough for me.