Pros: Comfortable, adjustable weight, no acceleration that I can detect.
Cons: Rubber coating is starting to wear away on the thumb area after 1 1/2 - 2 years of use, braided cable is starting to fray where it rubs on my desk
Great mouse, comfortable, feet are still functional and smooth. No detectable acceleration or prediction on a Steelseries QCK cloth pad. Adjustable weights are cool, adjustable DPI is great.
Starting to wear out now though, rubber coating is worn down to the smooth plastic where my thumb sits, the braided cable it starting to fray a bit where it rubs on the edge of my desk, but it's been good to me for a long time, so no complaints really.