I've never heard the MBRP in person, but I have the Borla with ARK mid-pipes and stock primaries. Also, using Akrapovic oval exhaust tips.
Adding the Borla over stock made it louder for sure, but better, more aggressive tone IMO. Sounds deeper at low RPM and comes alive at 2-3k. It made the car start to give some burble/rumbles on down shift or foot off, which is nice.
Adding the ARK mid-pipes made the sound deeper and the burbles/rumbles more frequent (I get them in comfort mode sometimes). More spirited driving will get a pop or two in sport mode. You can even hear the turbos from the exhaust if you listen closely.
Here's a video comparison I did a while back when adding the mid-pipes (Instagram).
I recommend the aftermarket tips for anyone worried about in-cabin noise. They really help the sound stay outside of the car (past the bumper) as opposed to reverberating inside.