With marginal improvements, anyhow, which you can read about (and in tremendous detail) elsewhere.
My experience, for what peanuts it may be worth, is that it’s behaving exactly as expected, which is to say it’s basically working as well as the old version; even slightly better. There’s some nice polish around the edges now—the new scrollbar behavior is probably my favorite feature—and speedwise it feels pretty zippy, too.
I doubt I’ll be actively thankful that I got the update. But no regrets, either.
Maybe this is because I had FileVault’s full-disk encryption turned on for the majority of the time I ran 10.7, but disabled it before I did the update. The system’s fast enough now, and it wasn’t quite before, so I figure why mess with a good thing? ↩