looks good to me. 15-12 is probably what i should be aiming at... I find I make more out of cut-off than the button as well, I put it mostly down to people letting me steal more from cut-off...

Is it possible you're making less on the button because you're trying to steal the pot on the flop and turn more often than you should be? or because your opening range is far greater you are playing worse hands than normal to the river?