I had the tone I wanted with the two HP2 mufflers, but not the volume and drone. Adding in the Super Turbo got me the volume and lack of drone but I lost all the tone I was after.
I could not tell you the performance difference though. The last time I put the header back on I noticed that the UG was only showing 135-138 HP. I need to log and send it in, but Vince seems to be MIA. I suspect the drop in power happened prior to the header going back in and it is possible that the ZZP cat is partially plugged. I dont know for sure though.