On my Birthday, best present ever, got the Stillen CBE installed (last week).
After many youtube viewings, sound clips, and user reviews, I knew before I bought it, this was the one. AND it was.
This is my daily driver, and as advertised, the Stillen CBE has zero drone.
Only comes alive when I want it to, and the sound (to me) is simply purrrrrfect.
YES, the cross-member did need to be spaced off slightly. I had it banging against that at certain RPMS, or bumps in the road. It wasn't constant, but homey don't play that. Added about a 1/4" washer on both sides. Nothing hits anymore.
Pics below for your enjoyment, the cross-member photo's are prior to spacers being added (which was fun doing myself with one arm/hand under the car)