I converted a scene I was working on over the summer of a Texas wedding venue. It's being built right now and thought it would be a good start for focusing on the render engine itself.
In the corona forums you can find some good conversion tools from Vray to Corona.
from downloading Corona Alpha v.7 to hitting render the whole experience took about 8 hours. 6 or so for learning and about 2 for the camera, lighting, material tweaks, and post.
I did some quick global color adjustments in Camera Raw, otherwise this was as is.
I recommend giving it a look while it's still free.