Running Trektop NX in the winter, no doors/safari mode in the summer, no problems. It's been a little over a year since I've gotten mine installed, and and it definitely toned down a bit, preferred the sound when the exhaust was still new, it was a bit more thoaty. I've been thinking of swapping it out for their Race Bullet.
Running the 3.8L, automatic, 4:10s, 35s. With overdrive off, the RPMs stay around the same when accelerating unless I mash the throttle, so it doesn't really get a change in pitch. It would definitely sound better as a manual.