Here's my 2011 Mustang GT with Flowmaster Hushpower Axlebacks and a resonator delete by a local muffler shop. Sorry for all of the background noise...it was a very windy day. I'll try to get a better video on an HD camcorder. There's no difference in sound volume at idle and cruising. You really hear the difference when revving and accelerating. It sounds a lot more throaty during acceleration.

There have been posts that removing the resonators makes the exhaust obnoxious, but if you notice, they have already removed their catalytic converters. Just removing the resonators increases the sound volume when revving and accelerating, but not nearly as much as removing the catalytic converters, and there is no issue with emissions/warranty. I have not noticed any increase in drone either.

http://www.youtube.com/watch?v=uhHZp0vtKwk

http://www.youtube.com/watch?v=mcFRghAPFJo