It's growing on me. I drove it quite a bit yesterday and am pretty happy with it. The drone is minimal, when I went to pass a vehicle on a 2 lane road it let you know that it wasn't stock. (kick it in the *** and it drops from 6th gear to 3rd)

One thing that I have noticed is that it points out how much the 6L80 shifts on a 2 lane road at 60 mph. (I live in a hilly area) It's not a big deal but when it drops from 6th to 5th, I hear it now. I never noticed it before.

 

Thought I would give an update on this old thread. I'm very happy with the Magnaflow cat-back. It has a slight drone but very little. That could be due to the guts falling out of the 3rd cat. Strange thing happened, when the cat-back was off, the guts of the 3rd cat just fell out.

I put an Airaid Jr. intake on it. It made it more aggressive sounding in the cab. The big difference, I think, was getting ahold of the PE table with HPTuners. I dropped the delay rpm to 2000rpm from 5000 and leaned it a bit. Now when you step on the throttle, it sounds like it has some a$$ to it and immediately lets everyone know.

Maybe it got louder on it's own, maybe it was the tuning. I don't care. It sounds good.