After using Vray since beta, I moved to Corona a few months ago.
I work solely in archiviz, and since moving to Corona I've spent zero amount of time fiddling with render settings, figuring out optimizations, editing out splotches in post - and instead I've spent time creating better shaders than ever, making better lit renders and generally just had a good time. For me Corona just... works. The whole workflow just fits me better.
I started by trying the free 45 day trial on a project, and it worked so well I decided to completely skip vray. I hear Chaos have a lot of improvements coming for the next version, but if the core mechanics of GI and image sampling don't change radically, Corona will still be my choice.