He was pretty much sold on the JVM before we got there - and once he found out he couldn't silent record from the Mesa he didn't even bother trying it out.
Yep - the 210H has 6 gain settings. It took us while to set the levels so that they were equal and figure out the dual master etc etc etc... After playing with it I don't know if I would bother with the 410H as the 210H seems to have enough variety for me with the 6 settings. I would probably never use half the other ones anyway.
The 210H has the exact same sound(s) as my JCM900 plus a bunch more high gain stuff which I usually use an OD patch/pedal for.