I've been reading in forums that Mesa does indeed have their own version for years.
First thing to consider is 8 ohm and 16 ohm speakers of ANY kind sound different between each other. 16 ohm speakers always sound brighter and more scooped. So if you hear people saying Marshall V30's and Mesa V30's sound different in their standard 4x12 cabs... well, yeah, duh. They're comparing more than likely 16 ohm vs 8 ohm versions.
It's only lately that people have really taken the shootouts seriously. It started with Nolly (from Periphery who also mixes some bigger Metalcore-y bands) who's really passionate about V30's and Mesa cabs. He mentioned that more than country of origin, it has to do with year of production. And that Mesa V30's sound close to the same than standard V30's from the same year.
Then this shootout came out. And his findings seem to agree with Nolly's.
Honestly, every V30 I've had has sounded good. Period. I've had a few V30's, but all from different years, and all different sounding. You really start noticing when you mic them up. Even speakers from the same year and the same ohms sound slightly different. That's an undisputable fact.
Then, there's the fact that cab construction make speakers sound different. You don't have to go too far. I have a Marshall 1960A that I swapped speakers in quite a few times. The angled top speakers sounded WAY different than the lower ones. Even when moving the same speaker around inside the cab.
It's all really confusing. I try not to overthink it. A V30 is a V30 for me. I personally like a Marshall 1960AV best in the room, but I like how a Mesa Rectifier cab mics up. I do like the brighter newer Mesa Recto cabs, though.
