Yes cycles is a pure path tracer. I don't think there is any bias but I could be wrong. The reason corona is noisier is because cycles has the option to render using your GPU card, specifically CUDA cores, which in my case is 450 cores parallel processing the scene on a 480gtx. Usually GPU renders steamroll CPU renders in time, the only catch being that the scene has to fit on the video card's memory (which is a huge limit!). So for corona to be very close to a gpu render is actually testament to corona's speed, imo. One of the best uses of cycles though is that it doesn't do any precacheing so if you make a change to a material the preview render will update immediately, its very nice for instant feedback on rendering.
Cycles uses node material setting, like octane or max. In blender you can create a node group, which is what I did here, I tried to get the node group to render the same as it would in corona. This scene was rendered/previewed in cycles then I ran my script which outputs the files needed for the standalone and then ran that. No tweaking to any scenes files after I ran the script(but you could for ultimate control).
The biggest problem is getting the settings to match from cycles to corona, for instance in cycles reflection glossiness is inverted and called roughness, but even inverting them they didn't really match so I had to do some noodling in the material group to get close. It's never going to be a perfect conversion but if I can get it close I'll be happy.
edit: also keep in mind no changes to configuration settings were made to either renderer, so its very possible I could speed up corona considerably, but I could also say the same for cycles.
