I have a Logitech G5. The bean shape and weight was hard to get used to coming from the smaller optical mice included with other computers (such as Dell for example). However, the laser and the ability to change the sensitivity on the fly is great and it works on practically any surface (even on your head, arm, or pants) and best of all, the laser never goes into stanby if you don't move it for a few seconds. It ensures that the mouse is always ready to go when you are, especially if you're a camping bastard who never moves >_<
It does have it's problems though, the middle roller button is rounded at the end and it really starts to hurt your fingers when you have to press it a lot. Also, the middle roller also tilts left and right. This might sound good, but I can't seem to get the tilting to work in games or in general use (it works on Mac computers, especially working on programs like Adobe Illustrator on a Mac). The problem with the tilting roller is that when you want to click the middle roller, it doesn't always work and it'll either register as a roll, or it tilts and doesn't register.







