I just went through an extensive test of the new SOLO Performance Axle back system on my car. THe drone in 6th is minimum under full load with AC on and will be in that ballpark when available (2 or 3 weeks).
I went to SOLO because the Magnaflow on my SKY has gotten dronier with age, i mean it always had drone. The full X-Pipe cat back I have on my car is sweet with NO DRONE.
Read here:
http://www.camaro5.com/forums/showthread.php?t=41041