Opinions on Dynomax super turbo cat-back system

I'm probably going to get the Dynomax super turbo cat-back system. But first, I'd like to hear your opinions on the sound, power gains, and anything else about it.

Thanks

I have the 3" Dynomax. Pics in my sig. It fits well and sounds good, not real loud. You'll want to get tips for it, their pipe ends look really bad.
Dynomax has 2 catbacks for LT1s. 17406 is 3", 17429 is 2.5 ".

I think Dynomax mufflers are great. I have a V6 that had one and for it just being the muffler, not the whole catback, it sounded real good. No rasp really anywhere, then again I have an auto so my RPMs don't jump too high. The power gains were noticable. From a stop my passengers would get mad cause they would get planted hard lol. I switched to a take-off z-28 exhaust and it was back to stock feeling.

I've got just the muffler on my car.

I have to admit though - I wasn't thrilled with the sound when I first had it on. It's taken about 10K or so to break in the muffler to the point where it's loud enough for my tastes.:)

How much hp and tq gains should I expect to gain from headers and this dynomax cat-back? I'll also have the cats gutted or removed.