My Dinan setup does not drone at all. It has a deeper sound at idle and very low rpm, but at cruising speed it sounds like stock. At WOT it is quite a bit louder than stock screaming all the way to redline. When you want it louder, just hit the gas. I absolutely love the sound! I think it is the best of both worlds with no drone. This setup makes great power too.
Of course this is just my opinion.