Is everything. If anyone's interested in developing a killer sense of timing, a good way to do so--besides metronome--is to play funk music. To me it's more fun than working with a metronome. Plus, it really does develop your rhythm chops because those guys will be playing the same chikka-chikka 16th note vamp straight through the entire 5 minute song. It seems really easy because usually the chords are really easy, but holding the steady groove in the proverbial pocket is pretty hard. That's another thing that I don't think metronomes convey---the pocket. My teacher likes to say 'there's guys that play on time, and then there's guys that play in time.' It's a lot harder than it looks.

Try it, who knows, maybe it'll work!