I have the Dynomax super turbo on my tj, At lower rpms 1k-1.8k its a bit deeper than stock, from 2k-3k its pretty similar to stock volume wise, then from 3k up the sound comes back in. Volume wise its not much louder than stock, but does change the actual sound a fair amount.
With my hard top on, I hardly notice its there. Sounds much better with the top off. All in all its pretty tame, and I think I will go slightly louder next time around.
As for Thrush brand mufflers, I have run a couple in the past and have always been happy with them. Had two on a old Nova with a 355 and also had one on a ...wait for it......Geo Storm!!! Sounded great on both, to be honest I was amazed how good the storm sounded.
Both are solid choices, dont think you can go wrong with either one