Yeaaahhh...computers have never been something I'm 100% confident with in music. Yes, things are WAY better than a decade or two ago, and I'm not even going to go into the strides made since things like Dyaxis were the only way to go. At this point, I've gotten past being jinky about them in the studio, but using one live still gives me pause. And HELL yes, there's a huge difference between a "virtual" device and actual hardware...which is one of the things that makes me chuckle when I see people blathering on about the virtues of "DAWless" work; c'mon gang, I was doing that sort of thing as far back as 1979, and you're just NOW telling me how cool it is? Ha!
As for VCV...I look at it both as a useful tool AND a teaching device. However, when a VCV patch starts getting into the turf where you find big Monster Case builds, VCV tends to overtax its host machine. But it IS useful as a sequencing environment, since my experiences with it have taught me that it's the sonic aspects that really suck down the cycles, and I've done a few tests of routing from VCV -> Ableton CV Tools -> MOTU 828 mkii with pretty good results.