I don't know why there is such loyalty towards a render engine always. The old battles between Mental Ray and Brazil was just as pointless.
It has nothing to do with which is better, because most of them today are all based on the same algorithms, it's just what else they do with them and how they package it that matters. Corona and Arnold is very similar in this sense.
Corona does an AMAZING job at being fast, easy and to the point. Here we are using Corona solely at the moment while waiting for chaosgroup to sort their shit out. Vray 3.1 had the right idea, basically adding the stuff vray was missing compared to corona, but they just didn't do as good a job of it.
Here I am talking about pure productivity, in features etc Vray will always win.. they do have 15 years head start after all, but in setting up an interior shot, lighting, drafts, getting a final out and post production. Corona just made my life SO much easier, and I have been using vray for 10 years, I could get the same result, I would just have to spend 2-3 times as long tweaking small settings, where now I can spend that time in post production.
So when it comes to the question of whether people are playing with corona or not, I don't see any reason why you wouldn't?! if it fits your workflow or not is up to you to decide, but that doesn't make it better or worse necessarily. At the end of the day it's great artists that makes great images, not the tools.
Personally I would love to stick to Vray, but chaosgroup doesn't give me much of a choice currently with the project we have on here.