I have the full exhaust....had it installed with just the stock OEM cats and now with BERK high flow cats. With the original cats, its a little louder than stock...one of the quieter systems I think, but sounds good when driving hard. Loudness picked up a bit with the high flow cats but still not as loud as other systems. I haven't experienced any drone at any rpm on the street or highway.
Video below is the full exhaust with the high flow cats stationary:
Video below is same set up from inside and track driving...on Nurburgring
Video below is same set up on a dyno pull:
Video below is in cab during a drag run:
Bitburg drag race on Vimeo
Last video is in cab again on a track....driving on Spa Francorchamps
Spa on Vimeo
That should give you some clue of what it sounds like....sorry don't have any vids from outside.