You can do your research to see what is available..
but my position, from my own research and marketing background, it's money.
VW Dual is basically regular VW positioned to work with a dedicated printer/cutter environment(something regular VW was lacking) versus a paid for RIP that is limited to one platform(Mac) and development limited to Roland's schedule/track record.
Compared to a more mature RIP like Caldera or Onyx, you may as well skip Print Studio for a more established RIP environment.