They are stupid good amps, especially given how cheap they are right now.
While I am still using the REF, it's not gonna be in this car any more. It's going into the upcoming "Project Blackburd that will start this spring with some other goodies.
Bigger the knob the bigger the bass, or so I've heard.
It's not the prettiest HU but seeing as it's going into one of the homeliest cars on the road I'm not too bothered by it.