Summary:
About a month ago I spent around an hour testing various mice at a Best Buy store. The mice I tested were mostly the same ones you mention in the round-up, namely the Logitech G7, the G5, Microsofts Wireless 6000, and the Razor Copperhead.

After I cajoled a sales rep to let me actually plug them into a working laptop, I was able to sufficiently guage the usability of each mouse.

The only thing I couldn't be sure of was the software packages they each would use, but I had a "feeling" that the Logitech software would provide the most customization, and I was apparently right.

I didn't care if it was wireless, so I quickly forgot about the G7 and was less than impressed with the MS 6000s features. The Copperhead didn't feel good in my hand either, and I was fairly certain I would feel pain after hours of use.

So, I eventually settled on the G5 from Logitech due to the comfort (I'm right-handed) and precision accuracy (up to 2000 DPI!!!). I must admit it took some time to break in the mouse, mostly the scroll-wheel was a little stiff, but now it's smooth and easy to use, without worry of unintentionally pressing it to the side instead of down. Logitech knows what they're doing, this is a great gaming mouse, and reasonably priced too! Unless you MUST HAVE a wireless mouse, I say go with the G5.

Pros:
G5: Custom DPI Settings, Custom Wighting, Excellent PC Software Package, Large and Comfortable

Cons:
G5: Not Wireless, Only One Side Button