Wow, what a great explanation of the whole process of rendering and anti-aliasing. I'm a self-confessed newbie, so a lot of these concepts are still a bit nebulous - hence the unnecessarily long render times

Quote - It is a very capable renderer. It supports global illumination, caustics, soft shadows, IES lights, lots of neat stuff in the lighting model. It has a pretty sophisticated material model, too.

I've only played with it a tiny bit. I don't yet know how to import Poser figures and such. I've only played with the built-in primitive shapes. RobynsVeil is way ahead of me on this.

"Way ahead" may be a bit of an overstatement. Actually, what I have done is what all of us probably do with new software: try it before reading the instructions. So, importing Poser figures was a bit of an issue, because the orientation is different.
Really Quite easy to use - simply export your model as a Wavefront .obj, making sure all your texture files (including bump and transmaps) are in the same folder as the obj file, and then just open the file in Kerkythea - it reads it natively. You actually have to turn your object 90 degrees on the x-axis for it to import properly. You can turn it once you get it into your scene, but it's easier to turn it in Poser first before you do the export to .obj, since Vicky has so many body parts.
Skin is rendered beautifully - as is any other texture. The only dramas I've run across is transmapped stuff, but only because I've never understood the magic. (I believe eyelashes also work on the same principle...)

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One thing I'm not clear on is how/if it does polygon smoothing. For example, when you load the built-in library sphere, it is very low poly. You can see this on the edges. I'm not sure that it has micro-polygon smoothing built in. Something to think about.

But what is very exciting is how it handles light! This is the number one reason to consider using it instead of Poser's renderer. Check out some of the gallery images on the site. The interiors really show off the sophisticated lighting model.

Strangely, there doesn't seem to be a single human figure rendered in their gallery. Maybe we can correct that? :)

They do recommend Daz and Poser figures on their forums. Since most of the Kerkythea users seem to come from Sketchup (architectural) and Blender (some Silo as well), the objects of render are more scenes with inorganic matter. Subsurface scattering and IBL as well as polygon smoothing seem more an organic model thing, perhaps... I don't know. 

Monterey/Mint21.x/Win10 - Blender3.x - PP11.3(cm) - Musescore3.6.2

Wir sind gewohnt, daß die Menschen verhöhnen was sie nicht verstehen
[it is clear that humans have contempt for that which they do not understand] 

Metaphor of Chooks