Huge! Not for someone who likes to hold the mouse with fingertips instead of using whole palm, however comfortable if you do like to rest your arm on the mouse.
Rubbery finish on the sides feels nice and the side buttons are in good position (easy to access and not in the way)
Scroll feels awful, it has clicks which are useful, but they tend to stick and it feels like something is grinding in there, maybe it will wear in but I'm not sticking around to find out.
Large feet, but for some reason not as slippy on my gaming mat as other mice with large feet.
Cable is too thick and stiff, it actually moves the mouse if I let it go on the mat. lol not good at all.
Easy, quick installation, not much to set up unless you are after something in particular. Simple to set up custom DPI settings.
Now this is where it really lost it's stars. I can't quite put my finger on what exactly was wrong with it but it felt completely different from any other mouse i have used, tweaked the setting several times and decided I just need to get use to it as it did track the movement very precisely with no jumping etc.
BFBC2, I found myself switching between the DPI setting back and forward as it never felt right and my wrist started to feel stiff from extra strain from trying to keep my aim steady.
After two days of use it goes straight on my shelf as a backup mouse. It might be good for rpg's and point and click games but not FPS in my opinion so look somewhere else, I'm getting another Logitech RX1000 as I had it before (broke after one year) and it just felt natural, the 1000dpi laser tracking was more than adequate for anything out there as well.