I started with a catted Bassani X and Stingers. I removed the cats about two months ago. I'm never going back. I don't think there's a better combination that sounds so good as the RPMs slowly rise when you're in traffic. Everyone is just like... whoa... Just my opinion though. ;-)
IMHO cats almost always sound better than no cats. With cats the sound is mellower and more crisp, without cats it's more raspy and obnoxious, which can be good and bad.
imo your setup sounds best with the cats as it really cleans up the sound and you can hear the blower whine so much better!!! But it does also sound good catless too, just in a different way.
I have ran my Stingers with both and to me the O/R X sounded way to raspy and retarded loud! Catted X FTW! Not the best vid but here it is on my old vert. YouTube - 03 Cobra drive bye
I think its the type of x-pipe used. The bassani and BBK sound like crap off road. The true x design like magnaflow, ARH, Kooks, etc sound much cleaner.