Hi Artur,
first of all thank you for this excellent tutorial!
You are my personal Hero in creating vue arts ;-)
I am a very beginner, but with the help in this forum it look like... i will survive :-)
I tried to make a cave with zbrush and it looks very good i think, but i used to much polygons for it. When i imported this to vue it colect to much resources.
This is my old problem... i do to much details in to much quality with to high resolution ;-)
But i try and try...
I have read your hints for render settings (also Peggy Walters' render tutorial) and my render times cut down dramatic... thanks for that!!

I hope you have some time for more tutorials!

best regards
floyd