@Humpleupagus @charlie_root It's a combination of saturation, mid/side manipulation, and a limiter. I't likely got a variable EQ to shape around the limiter and probably a clipper as well. At least that's what it's designed to take the place of. It's just aimed at making mastering loud easy without distortion being too noticeable. If you can clip each track and saturate, eq and limit on the master yourself, you don't need it. I tested it out and it's was pretty good on the tracks I tried.