I have had ART pipes and FI RHFC.
The ART pipes are obviously louder and I had a drone issue, but it was mostly in town driving in auto mode. The sound was very raw. Not obnoxious, but noticeably louder and meaner. The pipes themselves are a work of art and fit up was perfect. One advantage is the ART pipes use the oem style ring gasket. I have a Borla cat back and it does not have resonators, so I found the combo too loud. The ART pipes also have mounting points to reconnect to the stock bracing system.
You can't really compare cat pipes to test pipes, but I ended up replacing my ART pipes with FI RHFC. The cat pipes are much quieter. Still a noticeable change from stock cats. The FI pipes were a perfect fit up too, but use a flat gasket for the header to cat connection. I went with Z1 metal gasket, so that adds $50. The FI pipes do not use the stock bracing system.
I haven't had a CEL from either set. My butt dyno would say that ART pipes had a little more power, but that may have been swayed by the volume of the exhaust. Both sets have hiss on decel, the ART pipes were much more noticeable, but I like it.
I have some before and after video posted in the exhaust forum.
LINK TO THREAD
I will most likely be posting the ART pipes for sell soon, but need some more time with the other set before I make a final decision. ART pipes have 3500 miles on them, no issues, no scrape, no dings. If so, I'll take $450 plus shipping for them.