I haven't heard too many good things about them. I was going to get one just for volume control (my stereo receiver is out of reach) - but reading a few reviews, it tries to 'adapt' whatever application has focus. Instead you have to use the Powermate (which it's sole purpose is to send 'keystrokes' with turning the knob) in combination with a macroing program like Keyboard Maestro or AutoHotkey, to get it to control volume no matter what application you're in. I figured it was too much hassle for the price