I have one and flat out love it.  Way better than past attenuators and re-amp setups I've used with my amps.  I've tried it with my stock '79 JMP, my '67 blackface Vibrolux Reverb and as a power amp to run in stereo with my EVH 50w and a GMajor II and it works awesome for all uses.  Also like that I can use it as a power amp for ipad modeling apps, but I'm yet to try that.  This thing is a killer swiss army knife in one box.