I have the logitech G5 and I must say it's the best mouse I've used. I've never used a Razr mouse and have actually considered one, but with the G5's on-the-fly adjustable DPI up to 2000, you can't beat it.
No offense to you Odie, but I don't know what Cal-M in CSS has to do with making a good mouse though. I used to be Cal-M and I had a crappy logitech mx300...but then I grew tired of the CS drama and found life outside CS.