Well, I've never heard the prior versions of their offering, but I recently traded a piece of equipment for a new pair of MM De Capo BEs. All I can say is that these speakers are exceptional.
I've never owned a pair of serious monitors before, but I can tell you that the De Capos give up very little to my reference Daedalus Ulysses (only in the deep bass). Even so, the bass is unbelievable from such a small speaker, and they just disappear in my room. Imaging, tonality, and soundstage are excellent.
I've always been interested in hearing the 3A line, but they don't have a very robust distribution network. The only reason I picked these up, is that I'm moving to a smaller home next year and my Ulysses are too large for the new space. I'm really happy I did, and I'll be selling my Ulysses shortly.