If you have any extras like Glims or 1Password, you have to uninstall those for now or else you get crashes at launch. It’s nice that the ClickToFlash plugin still works though.
Having used it a full day, its been great, haven’t had it crash once. And it seems to render everything well and speedy. Cnet news and others are hating on it right now, but their real beef is that there’s no community with add-ons like for Firefox. It would be nice for Apple to get something like that going, if they want to be a serious browser competitor, or else their browser market share will closely resemble their Mac market share since so many "average" folks just use what’s on their system. I would imagine the Safari add-ons would look/feel nicer than the ones in the FF lot, Mac devs tend to scrutinize UI.
There’s still some things I’d like to see improved. Top Sites is cool, but it needs to be way more customizable. It’s ok I guess to have it default to fill with sites you visit most (kind of like a smart bookmarks folder), but for those who want to tell it exactly what sites you want, where you want them, it’s currently a pain. One work around is to open up the TopSites.plist and edit it, but that’s cumbersome too. Not as important, it would be nice to be able to put in your own screenshot or image.
Another teeny gripe is it’s too bad the blue progress-bar is gone, replaced with a spinner in the right side of the address field, which doesn’t give any visual feedback on the progression of the loading page.
Being able to control-tab through tabs is cool, but if your cursor is in a text area, control-tab only highlights the address bar, then control-tab again to cycle though.