Hated my Spintechs from day 1...I dealt with em for a couple months til I could figure out what to try next. I had just the mufflers (not the side exhaust) into a Flowmaster catback with an MRT catted H. It sounded just like a friggin truck, machine gun, blap, blap, blap, blap. Sure, it was loud...but lousy.
That's all gone now, sitting in the shed. A Borla stinger catback with an O/R X now under my ride - and I am finally happy with this setup.