I have my Magnaflow Comp cat for over a year now and still love it. No install issues perfect fit. As for the drone I dont drive around at 2k rpms so it doesn't bother me.
I've decided to pull mine, going with the GT500 axle backs (got them for the old price), custom over-axles, and leaving room for a catless x-pipe. Should sound wicked enough like that
I have a set of these and they fit fine and ZERO drone...this is my 3rd set of Magnaflows on 3 Mustangs with no issues. Workmanship is excellent....FYI