Rio95,
The combo I just swapped out was MAC shorties, BBK catted Hpipe, and Flowmaster 3 chamber catback... so it is definitely louder with non catted Xpipe, LT's, and Bassani's... From a scale of 1 to 10... my old setup was 5 at WOT, and my new setup is probably an 8... Its actually a little louder than I wanted... but, I can't get this damm grin off my face everytime I drive the car... The sound is just wicked... A nice deep lope at idle.. and a deep rumble as you go through gears at 2000-2500rpm... but once you mash it.. the car gets a higher pitched Exotic car scream... that just sounds nice... plus their isn't a hint of drone...
Its not for everyone, but definitely different if thats what your after...