I've tried the following:
stock h w/ bassani c/b
Catted X w/ catback
o/r X w/ catback
The stock h is still quiet with the catback and kind of disappointing after having the x in there. The catted x and catback has a nice rumble to me and is not too loud to wake up the neighbors just driving normally down the street. I've taken the cats out and used the o/r pipes from bassani and it sounds amazing but I was too afraid of getting pulled over for the being so loud and also the neighbors wanting to kill me. I have a clip of the o/r just starting up and revving a little but the sound quality is not that great. If you want that too just let me know.