The new version of RPR seems to render everything a little more "noisy" than the older RPR did.
Is this just because things haven't been fully optimised yet or is there a fundamental difference between the Blender 2.8 and the 2.79 RPRs that will persist like this?
It's not a bug... just an observation.
Both renders done to 500 iterations. Materials are not matching because the node trees are very different now.
A test using the Uber shader in v2 verses v1.8.
At 500 samples.
I believe the noise levels are comparable again.