I’ve tested RenderMan with spline rendering. it’s much faster compared with baked Geometry. the spline primitives are very good in Renderman.
I’ve stopped the test with mantra after 10 minutes, it is super slow even with optimized render settings.

the Renderman images rendered for 3:20 on a 6 core Xeon
2.7ghz with pxr pathtracer. 4k resolution
geometry:

splines primitives:

rendering splines directly saves a lot disk space and meshing time. interactive rendering was super responsive.
Octane 2019.2 renderings is very fast, I’ve used the geo to render it. 2 minutes, as except its lot faster the CPU renderings. the spline rendering in octane does features custom width yet.

Octane gives physical correct shading out of the box. Renderman the shading is extreme flexible with NPR renderings, which is hard to get in Octane. the IPR responsibility was a little slow with shader tweaks.