The PowerBond Unit also sold under Pioneer brand & PBM is the only damper I use other than ATI. It's my "budget" choice... have never had a single problem with one, even in 700-750 HP motors, including circle track use. I've probably used 35-40 of them.

I've had several Summit SFI dampers fail (slip).

http://www.summitracing.com/parts/PIO-872037/