I had a custom exhaust on my gxp and loved the sound but the drone was getting to me. I got a good deal on a full magnaflow catback exhaust. Honestly it's the best investment I could've done. I feel I got some power back and best of all my drone is gone. I'm thinking of adding a ZZP catted downpipe just for a little bit more flow since I've read the original is a bit restrictive. Any of you guys used this before and how do you think it would affect my exhaust sound and drone ? Thanks for any input.