A few quick observations after a not particularly long test period:

• The weird error in the results sidebar when using SpriteKit seems to have gone away.
• Code you drop into Sources seems to be visible without having to quit Xcode, restart it, and re-load playgrounds. This is a huge improvement.
• QuickLooked Bezier paths are still upside down in iOS playgrounds. 🙁
• Still plenty of DVTAssertion issues begging for bug reports in the OS X console.
• A nasty little bug when rendering custom classes in arrays to strings no longer happens. Radar be closed!
• Rendering documentation no longer kills value history panes when you go back and forth between the two (at least in my minimal tests), which is great because re-setting all of those up was annoying. \o/ to the playgrounds team.
• Rendering views on the iOS simulator still causes epilepsy and migraines.