A comment on the MX1000...
I've been using it for the past three months. It's an awesome mouse, yes. Best wireless response and all-around hardcore mouse ever. But first, the default drivers in 10.4.2 borked the MX1000, making buttons do things I don't want them to do, and having no way of disabling them. And sadly, the Logitech drivers blows chunks in my opinion. It actually slows down the response to the buttons I use for expose and dashboard. With the Tiger drivers, they work instantly, but under Logitech's drivers, there's a noticeable delay before Dashboard comes up. And the scrolling and side-scrolling is horrible with Logitech's drivers. Done beautifully with Tiger's.
All those are software issues that can be fixed or worked around. Now the hardware side, after using it constantly for three months, I noticed my wrist started to hurt after a day's use. The mouse, simply put, is too heavy. The mouse is designed for hardcore gaming, where you mold your hand to the mouse and use all the buttons. But for relaxing use, where you sort of move the mouse with your fingers, not your whole hand, it's really bad. Recently, the battery died (I neglected to put it in the cradle for too long), and had to switch to my Apple mouse for a bit. And WOW! I'm surprised at how comfortable and easy it is on my hand and wrist.
So needless to say, I decided to give up the MX1000 and get a lighter mouse, maybe an Apple wireless mouse, or the MX510. I don't want no carpal tunnel, thank you.