Magnaflow is 2.25" piping.
Borla is 2.5" piping.
Magnaflow is quiet at cruising speed and wakes up at WOT.
Borla tends to drone at cruising speed and screams at WOT.
I have had both and currently have a custom 2.5" piping with a 14" Magnaflow resonator and Magnaflow Muffler paired up with a HFC and it sounds great. Zero drone, and screams at WOT.
It all depends on what you are looking for.