I just had the SpinTech put on. Initially wasn't super thrilled, but it may have been because it has been years since I've had an exhaust on a car. I have been liking it more and more each day. I want to have someone drive the truck around so I can hear it on the outside.
As far as drone.. I'm not sure what it is exactly so I couldn't tell ya. One thing I have noticed compared to other users is I have no idea when my MDS turns on, no change in the note that I can hear. Also on the highway at above 70 I can hear the exhaust rumbling at a very low note, it is taking some time for me to get used to it. Under 70 or so you can even hear the exhaust on the interstate.
So far each day for me it has sounded better and better! The first day it sounded bland to me and now it has a much more aggressive muscle type tone.
I also like the fact I probably dropped 50lbs going to this muffler.