Fit and finish is really good. I've installed headers before, but this time I had a shop do it. The only issue was removing the factory studs (from what they said). There was a small burr from the coating on the flange. Easily removed with a Dremel or similar. Just cruising it doesn't any louder, a little growl when getting on it. Definitely felt like there was more bottom end.
Flowmaster Force II Axle Back Exhaust for 2011 V6 Mustang
Stock V6 Mustang convertible with a manual transmission. Couldn't stand the way the stock exhaust sounded. I've run Flowmasters on other V6/V8 mustangs, and love the sound. You'll never confuse the sound of a V6 with a V8 no matter what exhaust system you run, but the Flowmasters give the V6 a nice low bass sound at idle, and really wake up over 3000rpm. No droning at highway speeds, even in the convertible. Nice quality product that seems to last. Easy 60 min install with hand tools.