I've just got a Lava Cable and a Monster Rock to test along side my usual George L. I have to say, the George L is the loues and brightest, but the midrange seems scooped compared to the other two.
The Monster is a bit darker and has less volume, and has the most midrange, but good bass too.
The Lava sits in between, similar level to the George L, but less treble, more bass and more pf themonsters midrange.
So...George L seams the loudest and brightest, good for driving effects, not so good with brighter amps. I originally started using George Ls with Line 6 amps, and the extra brightness really helped with these early Line 6 amps. And it sounds the best with Guitar Port too.
The monster is great with the JCM800, it's a bright amp so the increased mid range and strong bass with reduced treble work a treat. Not so good clean, a bit dark.
The Lava has the most potential as an all-rounder. Good treble keeps clean sparkling, and increased bass and mids over the George L drive the amp well.
This is just on an initial couple of hours, and tested in a studio not on stage!