Personally, they're not very close, by sound or design. I owned a vtwin a long time ago, and it didn't sound or feel like any recto I had ever played through. The recto can be a very raw, loose, and brash sounding amp, and its not that easy to play at times. It's Mesa's take on the SLO100 (they used the core preamp from the SLO, and mated it with slightly different poweramp), where as the vtwin is actually very close in topology to the Marshall valvestate technology, so it's really an apples to oranges comparison. Plus you are missing half an amp with the vtwin.