Had a catted JDL UEL on my previous FR-S. Sounded quieter than expected with the stock front pipe and Perrin catback. Fitment was great. Gains were much less than the catless version per my tuner. Ended up blowing up the cat after 6 months. JDL repaired the header under warranty. My car was NA. I’d go with the catless version for bigger gains, and just keep the second cat in the front pipe.