Vortex Sound Research

I've been considering the Castle for a few months now, watching videos etc. For those out there who have owned one, what do you think?

It seems like a pretty unique module, but if there are others that do something similar I'd love to hear about those too. Of course I'm aware of Akemie's Taiko (I happen to own one) -- I love the sound but it can feel a bit unpredictable under modulation.