Old renders, actually, it was my first renders with Octane. Models by Bertrand Benoit. At the time I was testing the GI. How many depth do we need to have a realistic render without too many render time? Conclusion: it depends of the scene, of course, but most of the time, diffuse depth 3 or 4 maximum (2 or 3 bounces).
And, I played with the shaders parameters, because, well, it is what I like to do.