I think I need to edit the word argument to discussion in your post.
........as for entering the debate, I'd keep the exhaust he has on there.....why?? cause one he gets a h/c/i that'll utilize the 3 inch to the fullest extent he'll be glad he's not having to buy exhaust all over again.....we all know we constantly change out combos in the quest for more power, so why not keep parts that'll support a bigger and better combo. I could of saved a lot of money early on had I done such