Good mouse - it tracks well over some black mousepads that the first generation laser sensor in my MX1000 had trouble with. This is my favourite Logitech shape. The scroll wheel has a nice mass - better than the MX1100. AA batteries good for hot-swapping the middle of a session. I always forgot to put prior cordless mice back on their charge cradle until I ran out of juice.

Dislikes: AA batteries make this a bit heavy, but some like that. No spot inside the mouse to stash the receiver when not in use. There's a physical switch on the bottom to release the clutch for the click wheel - awkward. The VX Nano is better with the middle toggle for this. Tt's only for righties. They don't make a left handed version like the MX610.