I don't know about the new Intellimouse, but I've just switched from my 5 year old original Intellimouseone to the MX518. I'm no pro gamer and my mice experience is mostly limited to office kit.
Having been burned twice by useless wireless mice in the past, I wanted the cable. Needed to be big as well, as my hands can get cramp within seconds of being screwed up over a small mouse.
Right handed, the mouse is gorgeous. Better than the traditional 'curve clockwise' Microsoft mice that cant be used left handed. The two 'shoulder buttons' will take some getting used too, but I already quite like them.
I use right handed for gaming, left handed in windows. I actually quite like the feel of it left handed but it isn't designed to be used this way. The shoulder (backwards and forwards) buttons are difficult to use left handed as they are meant to be pressed with the thumb when used right handed. There is also a button in front of the wheel which should be useful in gaming, but I haven't installed the software to get it working. I might do so so I can map it as a left shoulder button.
Mat? Hmm, it might exceed my case and monitor as the longest standing component in use. Cant help you here.
