I just had my jones turbine 3030xl installed and resonator removed. It sounds awesome but its too windy outside to make a decent video.
I had them leave the flapper in, but I have it held open with a screw currently. They put the flapper after the jones muffler and when its closed it sounds really bad, like an air gushing sound. I tried it on the highway and the drone was bad with the flap held open. I would like to keep the flapper so, I'm taking it back to have them try it in front of the jones muffler to see if that helps.
Edit-
For anyone who cares to listen here's a warm start video.