This thing is a SAVAGE BEAST - which is a quality most players don't want out of a compressor (I'd say most guitarists/bassists want their compressors to be transparent and not obvious). However, for what I do, this thing is perfect; really heavy squash-y compression, and a really crazy sustain knob.
The Normal/Treble switch is the Icing on the cake, it gives you two vastly different sounds. I use mine on bass. Definitely one of my favourite effects ever, but it's not for everyone, hence why I can't give 5 stars.