Sketch render animation problem happens to me too -- that's nasty, the program locks. Creating the animation works fine in P5. (While performing this test I chose to render quarter size and noticed P6 prefers the alternate spelling "Quater."

Other P6-isms that cause P6 to feel sluggish compared to P5 include:

Startup time, twice as long as P5 even though my P6 runtime is smaller than my P5 runtime.

After clicking File/New I have to click the bar on the libarary palette with the "down triangle" twice to get the pull down menu, only once in P5.

After double clicking on a material library preset from Basic Materials, the nodes may or may not appear right away in the material window. Sometimes the nodes stay invisible until I move the mouse.

The render settings Load Preset button at first revealed just a horizontal line, then after I saved some presets, the standard Draft and Production choices just appeared above the horzontal line with my presets below the line. Now after SR1, Draft and Production are gone again and I can't get them back.

All that said, SR1 installation went without a hitch, and seems to have fixed the refraction artifact problem I was having.