So far so good. The one issue I have is there seems to be a bit of resistance when you first push the ball, which means the initial movement is a bit of a jolt. For most stuff it isn't an issue, but for work I take a lot of screen caps of windows for documentation, and I'm finding these a little trickier to get them accurate first time. I find if I pop my ball out and give it a polish it works a little better, but I think it's the machining of the plastic casing of the mouse that's the issue. I do like it though and have gotten used to it very quickly.