I don’t know if this is new or has been there for a while since I have not been testing or using Cycles (Raytraced view mode) too much. But tried recently and with the latest V6 RC3 installed, noticed 2 things that make it super slow and tough to even try to use:
When rotating the view and auto-switching to Rendered mode for speed, the performance of the temp-rendered mode is MUCH slower than if I actually switch to Rendered mode, so it’s not that much of a speedup for vport navigation in Raytraced mode
interference with compiled script commands: using many in-house tools that are compiled RhinoScripts - it seems that unlike regular Rhino commands, the compiled script command-line actions have to “wait” for each Raytraced step to move forward, making these commands super slow and unusable in Raytraced mode (for example MultiviewCapture script we use to automate capturing many named views at once) - navigating the command line options in raytraced mode takes forever. I hope there is a way to make the script runtime independent of Raytrace refresh speed.