I use a Virus B and it's awesome (I have the keyboard version). The synth engine in the non TI virus isn't all that much different from the TI machines; the TI ones have more polyphony and a few shiny extras, but in general they sound very similar.
I don't miss (or need) the TI features at the moment. I use my virus for drum and bass and dubstep, mostly by playing riffs on it, and recording some pitchbend and modwheel midi action into ableton. I then play back these clips while messing with the LFOs, filters, osc settings and dist settings on the virus. I record all of the results as audio, and cut out all the good bits into basslines. These then get a bit of compression, reverb, maybe some further automation applied to polish it off. This is a fine workflow for me, especially since I often end up mapping the ableton clips to the keyboard and just playing the wobble basses until I find some good grooves... I Love tweaking knobs, hate fucking around with the computer, so the thoughts of TI stuff isn't very interesting to me.
The sounds of the virus are sick for dnb. You might end up recording some of its sounds, layering them, and taking it a bit further in a sampler anyway, or not. Depends how you like working and what sounds you are after. But the price of the TI stuff is totally not worth it in my opinion.