i guess it all depends on what you think Vray will give you that mental ray doesn't? I still am new to Mental Ray no doubt, but hearing all the good things about Vray it does makes me wonder. I spoke with a friend of mine very quickly, he's the only Autodesk Certified Instructor here in the city and in our very short conversation he just said is fast and easy to use. Sure, but I would also love to hear your opinions if you use Vray and if is really worth to have a go. But the main thing is the Real Time preview that I'm most interested. Being able to see the results almost in real time is just fantastic and really speeds up your workflow, specially with the settings.