Man, if guys from ESReality.com came here, they'd eat this whole thread alive. No offense, guys, but audiophiles are best-suited to judging audio gear and gamers are best-suited to judging gaming gear. I had just a glimpse of some of the things said here and cringed. For the record, Razer generally isn't durable with just a few exceptions (and neither is Steelseries); lightweight mice are generally the best choices for FPS games because they're easier to physically control, especially if you're a low-sens gamer; and most importantly, all laser mice have tracking issues. Go infrared optical, folks. Lower CPI ratings on average (Although not always, as the G502 proves.), but most of them have flawless 1:1 tracking and are thus more precise than laser-based alternatives.
I can see other mice working if you're just using them for their ergonomics or productivity features, or you happen to play MMOs and require a ton of macro buttons instead of absolute tracking precision, but if you're using these things for RTS or FPS gaming, or anything else that requires minute precision, opticals are really the only way. This is the general consensus of the gaming community. Laser mice have acceleration issues, some have Z-axis tracking, and they're pretty picky about what surfaces they work on. Yeah, true, they can track on glass, but often jitter to insane degrees on surfaces which aren't mostly flat, including a lot of cloth mousepads.
I tend to use this site to learn about audio gear, and I'm glad such a resource is available for the masses, but its specialization is audio. For mice, I recommend instead that you visit ESReality.com or Overclock.net. One of the best articles I've seen was on Geekhack, though. (http://geekhack.org/index.php?topic=56240.0) Geekhack, Overclock.net, and Deskthority are great places to learn about keyboards, especially mechanicals.