Sorry, but no! Tomei ELH is not going to sound dramatically different than XXX brand on stock catback.Well, I guess the brands matter then because mine is noticeably quieter everywhere compared to stock. I have a Grimmspeed limited catted DP and aFe ELH with the stock catback. I ran just the DP for a while and it was a little louder than stock, but the headers quieted it back down.
Why don't you record a clip and let us here this quieter sound you speak of.