I just picked up a VC last week to go along side my 100w MC2, so I'll throw my 2c in the ring!
My VC has the Master Volume on the back, but there isnt a boost.
While they sound like Wizards as soon as you plug them in, they are quite different sounding amps! First thing is the VC has a whole lot more gain than the MC2's rhythm channel (without being on ear bleeding volumes). With the boost on the MC2 engaged, there is still isnt as much gain but the gap does close a bit.
I find that the MC2 is all about having a huge low end, where the VC has a bit more guts in the mid range. It feels to me when playing that this difference comes down more to the voicings of the different models of amp, rather than one being a 50w and the other being a 100w, but I've never played a 100w VC to justify that claim.
As an added bonus, having both amps running together compliment each other extremely well. Both amps are super tight sounding and they both have heaps of clarity (a touch more in the MC2, but again, 100w vs 50w). If i could have one amp, it would be the MC2, but the two amps go together really well and in my experience are quite different sounding amps.
Hope it helps! there is so little info on the VC amps