You said that Marshall is a front loaded cabinet? I happen to like V30s front loaded better (I prefer the Engl to the Mesa cab, tbh).
You're right that my ears don't lie I'm not partial to any brand or anything of the sort. What matters to me is the tone. Like I said, turn D up in the mix a little, and you've got a winner.
I'm late to the game, but in both cases I preferred the Marshall clip. It sounds like you have a really nice cab there and glad you did not have to get rid of it in the proposed trade.