Does your computer match their minimum specs?
I think it's almost there, "almost" being the operative word here.. But the thing is that a lot of music today is created not so much by playing but rather by editing. And that used to stop me from trying, I preferred to play my arranger coming up with songs. It didn't feel right to work with music without actually playing it. But I see that today's composers, who actually make their living by writing music, mostly work with VSTi. I know that you can actually play the VSTi; what I mean, it's still more work with MIDI data, adding and fixing automations, etc. Since SX900 didn't solve all my problems and is actually away right now, I abandon all my believes and follow the principle "do what you can where you are with what you have" :-)
Since you have your VSTi up and running, I want to ask, what do you spend more time playing: your BK9 or your software instruments?