I have had a few different exhausts, and the only thing to do is get to a meet and listen to them. Videos do not do them justice IMO.
Scorpion = Great bark when giving it the beans
HKS (Replica) = Nice rumble sound when pottering, gets much louder. To droney for me
Milltek = Sound is getting much better every time I go out. Closest to a Nismo sound.... but half the price