I got a G5 and generally like it so far; however, I basically upgraded from an MX518, and to be honest, I can't see a huge difference. But the G5 does seem to have nice extras I haven't played around with (like the ability to use the various weights to customize the feel and balance of the mouse), and I'm sure the laser is more precise (I am just not sensitive enough to tell the difference between it and the MX518). I think you can't go wrong with either. I generally don't like cordless mice (I had used an LX500 for a while, and it was just too frustrating).