It seems to have subtly broken TreeStyleTabs on OS X, which is a shame because I am addicted to it, but at least it's still usable (the tabs take up ~150 pixels of vertical space). Hopefully this will resolve itself with a TST update.

That said, wow, the OS X improvements are huge. Previously I could only force quit if I wanted to shut down to free memory or whatever, but now it closes normally. I'm also not seeing the same kind of memory usage, but it's early so I'm not sure how long that will last.