I have an MX1000, starting to wonder why it was so expensive.
The only thing I really like about this mouse is that it's wireless. I only bought it to use from bed.

It is comfortable, but only if you're sitting upright and using it properly, it's not always comfortable when you're lying in bed.
It's a bit big, and pretty heavy.
I haven't yet found a way to assign the many different mouse buttons to different keystrokes in different games.

I used to have an MS Intellimouse Explorer before, got it for like £10, and it was brill. I would have kept it if the wire had reached my bed lol.