I'm not sure I seen any scientific experiments with controlled variables in my searching but just reading guys (mostly c5/c6 vette guys) talk about owning cars with both systems on different cars at one point or another or riding in other friends cars (again, similar engine size, mods, gears) they were pleased and noted no difference is spool time. When you do searching and find the guy that put a holset 35 in the place of his muffler on an ls1 Camaro with 3" exhaust and bitches about not spooling up until 5k..... yea, rear mounts are going to get a bad rep.

