Side note:
all my PC as a I7 970 @ 3.9 Ghz (default is 3.2)
I7 970= Corona Benchmark= 4 min 30 sec.
New i7-5960X CPU @ 4.4 Ghz = 2min 17 sec.
I call it +95% Performance.
I think PixelMango needs to upgrade his knowledge ;-)
I can say with honesty: I am (well, was ^__^) one of the most experts in VRay. I wrote what for many people is still the best book of V-Ray. V-Ray is a great rendering engine, really huge. But, lately, it has become too complex. For this reason, I decided to leave it. Because I was tired, very tired to spend so much time in the settings and render tests. This is true, there are many features that Corona, from my point of view, will not before a few months, if not years. But for the kind of projects that we do, for now, we are very pleased with Corona.
I used VRay from 2001 until 2012. Yes, 11 years! And it was the best, especially in a arch-viz. Then, being an entrepreneur, I am looking for the best tool that, with the least economic effort, let me save you time, giving me the best result. I found Corona in 2012 and since then use only that ( I cannot support two engines. We are too small and no need to have two library). I don't do it personally, but, If between 3-4 year I'll find out a better renderer like "Nastro azzurro renderer" ;-) I will abandon Corona.
Obviously, especially those who have interest in one or another rendering engine, they are trying to pull the water to his mill. I say to everyone, work with seriousness and honesty, avoiding wars. In the end, the chickens are coming home to roost .