Seriously, corona is running great on default settings. I used it for 2 interiors already, and I'm doing some product shots which I converted from vray. I tend to use progressive method only to check how far I need to go with different materials, lights etc. Only one change I tried was MSI 200-800 after some reading about Juraj's workflow. Well also beside I can just cancell rendering when I find it good enough.
Cheers