I traded my Borla touring mufflers with a guy who had the ATAK's. He had LT's and a stock mid pipe and he said it was very, very loud. The PC might tone it down a bit, not sure.
Yeah I don't care much about sound as I do performance. Although obnoxious sounds aren't what I'm going for... I imagine it will be a bit deeper and mellow. Hopefully after these I'll get gears and I should be good for a while.