I run mine with one Mills 2x12 and will put it up against anything I've heard before. I can't imagine two of 'em at the same time. Of course, the only time I've ever heard mine (or any V) through a 4x12 was at the store, when I bought mine, and it was crazy good sounding at low volumes. It has to kill at stage volumes.
That said; I've never heard any (real) thing bad about the vertical 2x12's and can't imagine two of them would sound bad with the V.
Hook 'em up and let us know...