Q-rack
I have a Q-rack and it's IMO the best VA-synthesizer so far with almost unlimited sonic possibilities.
The virus B is one of the most popular VA-synths probably since it contains alot of good presets that the Q (not currently) have.
My opinion is that if you know how to create sounds and want to explore new dimentions the go for
the Q-rack (it has a really good step seq also).
If you want to quickly start making music with your new synth and don't want to experiment and fiddling with stuff like fm and modifiers the virus B is for you.
Remember also that the soundcharacter is different for these two monsters. It all depends on what kind of music you make.
Also the Q can only have fx on the 4 first instruments of a multi while the virus b can have fx on all parts... but the we have the discussion on how good the fx are and I claim the Q to have better!
The Q isn't finished yet, OS 3.0 will be released probably next week adding lots of features like new reverb and so... waldorf will continue developing it and ading user wanted features for a long time.
So... don't read the specs of the machines... donload the demo mp3s to get a picture of the soundcharacter... the try them out! Tweak the knobs and don't let any "impressive store presets" fool you...
My advice is the Q but it's up to you
Best Wishes!
Johan Spång