For extreme high sensitivity (3200 to 4000dpi) either Razer Lachesis or Logitech G9, I'd pick the Razer Lachesis.
for medium sensitivity (1600-2000 dpi), I'd say Razer Deathadder or Diamondback 3G vs Logitech G5. I personally own the Diamondback 3G and I love it so much, if it crapped out on me right now I'd just buy another one.
I like the MX-1000 as well. I just upgraded to the G7 because I noticed the battery of the MX-1000 was starting to lose life. It used to last about a week and a 1/2 now it's done in like 3-4 days. Also, the MX-1000 started to get flaky. Mouse wouldn't move, jump around, etc. However, the G7 mouse batteries last about 1 1/2 days. Only good thing is it comes with two so you have one charged and ready when the other dies. It has a boost battery charge switch so it only takes two hours to charge the battery. Batteries swap out in about 6-10 seconds. Not too bad of a deal. Only other serious setback, if it matters to you, is it does have one less button than it's corded twin the G5.
After I went from a corded mouse to a wireless and laser, I never looked back at my Microsoft optical. Oh, did I mention that I'm a Logitech fanboy?!?