Who says that you can compare Vue's renderengine with Vray when they are two very different things?

With Vue's spectral atmosphere (standard now I'd say) the engine has to handle MUCH more than most faked-sky scenes I see created with Vray or Maxwell or whatever.

So I absolutely doubt the assumption that Vray would increase renderspeed for full blown spectral outdoor sceneries.

I thought Vue was lame but then you look back to Terragen2 which renders much slower for what you could equally create in Vue maybe 1/3 of the time.

and once again, excellent post, alexcoppo.