I went with the magnaflow rock crawler cat back and y pipe. I definitely noticed a horsepower increase, but it did come with the dreaded drone noise. After a bunch of research, I added the stock resonator back in and it deepened the sound note and made the system quieter with out much loss of power. Both the resonator and the magnaflow mufflers are straight through designs. Now I love it!
2015 JKUR AEV
I've never noticed a horsepower increase with a cat back system, but then again, I don't have a dyno in the garage to measure it.
What's the quietest exhaust available for a JK? I'd be perfectly happy to crawl over rocks in a silent bubble of bliss. Also want to ditch the stock one to clean up the back end