For the price of the Mediastation you are better off getting a decent weighted master keyboard and then some sort of PC/Mac or possibly a laptop with fast processor, memory, hard drive etc and using the VST plugins and software on that midied to the master keyboard. The price would be roughly the same, a PC and Mac could run more VST programs as the Mediastation does not run every VST out there, I think it depends on Linux again. A computer would probably be more reliable as well.
I have loads of VST's and only 1 worked in a fashion with the Mediastation with a little help from Dom setting it up which was quite hard for both of us. Having seen the B3 organ plugin I think it was called on both the Wersi and Mediastation, Wersi was by far easier to operate.
It would be nice if some of the bigger manufacturers jumped on the VST/plugin bandwagon though, this seems the way to go for the future.