My choptop came to me with a Flowmaster 40 on it. It works, not very loud at idle but when you get on it, it makes a lil noise. Not too bad though. I'd be inclined to get another.
My F-150 came to me with a glasspack.... I don't care for it that much. It doesn't sound really bad because I'm stuck with low rpms anyway (long live the 300-6), but...
I don't really like the length on it either, it's too long to let me exit my exhaust in front of the back tire the way I want to. But I haven't messed with it yet, had plenty of other things to work on with the truck that were more important. When it falls off I'll prolly put a 40 series on it or pick something else.