I agree. The scrolling is not as smooth as regular mouse, the scroll speed is not adjustable but I think is usable, the ball IS plastic, but my buttons are NOT falling off.
If you buy this product expecting to replace the mouse/trackball you have on your system, you WILL be disappointed.
Buy this product if you just want to make simple mouse commands remotely (like watching TV/changing channel, music selection/adjust volume, etc).
It is NOT a full time pointer replacement, but rather a very useful remote and THAT'S all.
Regarding the music controls, if winamp controls can be shortcut-ed or keyboard mapped, I don't see why it wouldn't work with this remote. I don't have any winamp things mapped on mine, but if you want to make sure, I can go home later (about 10:00 pm) and try it out and tell you for sure.
gluck.