Just got one.
Complaints
The right side buttons might as well not even be there, for me.I cannot comfotably hit them while keeping the left side buttons within range.
The software does not support per-executable configurations; which is something that I am accustommed to.
The software also plays hell with my Intellepoint 4.10 software, which drives the per-execuatble configs for my trackball. I circumvented this by disabling the Razer in the device manager until I'm going to use it.
Pros
REALLY comfortable, except for those right side buttons.
Pretty good software, supports macros. This is something that I'll take full advantage of.
It really is that accurate. At maximum sensitivity it is insane.
I map the right side buttons to acivate the real-time sensitivity adjustment via the mousewheel. It;s nice to instantly adjust my movement instead of running to a menu.
It'll be a while before I fully adjust to it, because I'm just not gaming much at all anymore, and I'm so used to my trackball. But I played through the Doom3 expansion with it two weeks ago and the Razer performed very, very well.