It seems like this new Mesa is considerably different under the hood than the AC-15 / Tiny Terror type heads. The new Mesa is described as Fixed Bias, which means that it will have a much different characteristic than the cathode bias power amp sections in the AC-15, Tiny Terror, Tweed Deluxe, etc. No mention of negative feedback or presence, but it might be in there. Plus, there are a LOT of preamp tubes in there, presumably for the dual channels. This seems more like a tiny version of the standard Mesa amps, rather than Mesa's take on the Vox type heads.
I have a fender silverface twin, and have been looking at small watt boutique amps to get some classic higher gain tones -- especially some old vox and marshall type sounds. I don't really care for Mesa's high gain sound, but if this amp can get in the ballpark with the classic tones then I might bite.