With VSTi's in general, I don't think these VST versions of classic hardware are actually worth the hype. From what I've tried, it seems better to use something that never had a hardware version, like z3ta+, Pentagon, and Linplug's things.
Moog Modular, V-Station, Pro-53, PPGWave and things like that just seem to be too awkward on the user interface, or they take up too much resources, or it's very difficult to shape the sound you want from them. They're just gimmicks to me.
A synth which offers plenty of flexibility like a matrix to route various controllers to sound parameters seems to be used more on my computer these days. After trying out most VSTi on the market, I'm whittling the list down to the ones I'm using most and getting the best results from, and that mostly just z3ta+, Pentagon, and a sampler (Halion).
I know the virus would be good as a VSTi - the original hardware was/is so popular because it was so versatile, and so the VSTi would be also. But, there's already VSTi's out there which rival the Virus, so it wouldn't be so viable. I certinaly kow there's one or two VSTi's which emulate the Virus. It's identicle in structure, it just has a different look.
K