I wouldn't compare the UI/workflow of Vray to Brazil. Even one of the guys from Vray admits they need a UI overhaul, while the Brazil UI is nearly identical to that of Brazil for Max. That could be good or bad, dependending on your point of view ; ) Modo's UI really is something on a higher level, being able to configure however you choose to. Definitely a cool feature, but overall not very important to the resulting image.

My workflow is normally to stay in Rhino as much as possible. It's gotten much more practical now that I started using Clement Grainer's mesh unwrap plugin. If I need more advanced UV tools then yes I will mesh the objects (sometimes in Moi, sometimes in Rhino) and send to modo, then return to Rhino again.

Also I just started using Fry and DAMN the results are so good. Will be amazing if modo finally opens up an SDK so Fry can plugin to modo. Imagine setting up in modo, click render and start Frying! : )