The Remus exhaust will sound deeper for sure, and it will have no drone whatsoever. I can't speak upon the RPI, but if ti's like the Z4M's I've driven, and M5's I've driven with RPI exhausts, there could be lots of drone. The Remus will not be as loud, but it'll have a nice low, and deep exhaust note, and from knowing this forum pretty well, I'd say most would agree that Remus is the way to go for quality as well:


Remus Sport Exhaust E60 520i, 523i, 525i, 530i, 545i, 550i



If you have any questions, please do not hesitate to ask! You can reach me via PM/Email or call me direct at 714.582.3330 extension 8002, and ask for Jurrian!

__________________

We Specialize In:
BMW Wheels | KW Suspension | AE Performance | Remus Exhaust | Forgestar Wheels | BMW Angel Eyes
Jurrian Terpstra | Jurrian@ModBargains.com | (714) 582-3330 ext. 8002
Hours: Monday - Friday 8:00am-5:00pm (PST)