Safari 4 Beta: first impressions

After reading about it all over the web, I just downloaded the Safari 4 Beta. Here are my first impressions:

• The installer required a restart of the machine. Let me just repeat that using some different words: I had to reboot my machine at the end of the install. If there was a warning about this requirement, I missed it.
• Safari 4 Beta is installed over the existing Safari 3. I don't know if Safari 3 is archived somewhere so that it can be restored if I uninstall Safari 4 Beta, but, again, if there was a warning about this, I missed it. If I find the beta to be buggy or unstable, it's not at all inconceivable that I might want to uninstall it and revert to Safari 3 while waiting for the non-beta release. I sure hope this is automated by the uninstaller.
• The progress-meter-in-address-textfield, which I originally hated, but grew to love, has disappeared. There's now a spinning wheel at the far right of the textfield, which obviously conveys no information about the state of completion of a page load.
• On first load, I am presented with a very nice looking matrix of ‘Top Sites’, though I don't know where these are coming from. I assume it's from my own history. GMail's front page is depicted twice. Four of the twelve slots are blank, which is surprising, as I am sure there are more than eight URLs in my history. Oh—hang on, there are references to pages (though one is just recent, a page I have visited all of once), but four of them have no thumbnail image.
• There has been some commentary on the new placement of tabs. With the caveat that all I've done so far is open the application, my first response is that it's not a look that I like. I'll reserve judgement until I use them.
• Develop > Show Web Inspector now appears as a pane in the lower portion of the window, rather than as a separate window. I think I like this.
• There are some interesting demos of new CSS features about. Presumably no other browser will support these, and hence they will be useless, for about a decade.

If I keep it around, I will post some second impressions later.