I've already tested a bit.
The interface gives a nice feeling. As I'm used to Maxwell I find the material editor a bit odd, with too many "models" when Maxwell has one that works for all the materials (which I think is what it should be: one ring to rule them all

). It has some procedurals

; I like the color lab with its fantastic (at first glance) spectrum color selector. I also tried 3dsmax plugin which I find a bit green yet but with some interesting features. And yeah, caustics through water show quite fast.
Max, you were beta tester, right? What do you think about it?