Installed FI 12" resonated mid pipe, replacing my unresonated. With long tube headers, it was LOUD and had a lot of drone from 2200 - 2800 rpm, making it tough to drive for long distances (full disclosure: I really enjoyed it most of the time, but I do have to think of my wife occasionally). Also put on the z1 transmission mount.
The sound decrease is remarkable with the 12" resonators. I was stunned at what a difference it made. I'll miss shaking homes and small children, setting off car alarms as I cruise by, but the plus side is I no longer fear driving to Zdayz this May.
But the real hero here is the transmission mount. Love it! Way less movement from my trans, solid shifts, etc - you've heard it before, but it's all true. I'd previously installed the z1 bushing collars and I'm starting to get the cumulative benefits of these small mods. Next up are the diff bushings, but I'm not looking forward to that project