The RAM question is a good one. I’ll check with the folks working on that feature to see what they say.

Yes, the caching does work for layers backed by .c4d files.

It’s comparing apples and oranges a bit, but… Yes, Cinema 4D rendering is faster than the ray-tracer for the cases where it would make sense to compare them. We’ll be getting into some details about when each workflow is appropriate, but one point is that the ray-traced 3D renderer in After Effects is still the best way to get certain results that depend on refractions and reflections.