They look good, particularly the grouped buttons. The shadows from the neighboring grouped buttons are a nice touch. I think it might look a little bit better

They look good, particularly the grouped buttons. The shadows from the neighboring grouped buttons are a nice touch. I think it might look a little bit better if the noise pattern didn't disappear on the buttons' down states. The noise pattern is essentially simulating a rough surface, so it seems a little odd that pressing a button would cause its material to change. Try zooming into the play button in iTunes. It's a good example of a button with noise, even in the down state.