I love the 7100 series!!! It gives it a nice DEEP grumble when I really push the gas hard, and is still civil enough to listen to the radio while cruising.
As far as athe approach angle, it is 2" lower than the stock manifold, but longer too. I've got the waranteee on it for 2 yrs, and the guys who installed it said that if I managed to damage/dent it on the trail, regardless of what I was doing, they'd replace it no prob. They said it was a pretty stout piece though and could take a beating....i dunno bout that, but it does look VERY well made in terms of beef.