A big one: no more "Easy Passwords 1.x compatible password" here, weaker password generation is gone for good. If you still had any legacy passwords these will be converted to stored passwords now, same happens when importing backups with legacy passwords.
Selecting a site got its own tab now, so it's visually different from choosing an alias for a site and should no longer confuse anybody.
And PfP options are part of the pop-up now. You can still get to them the way your browser lets you configure extensions. But quite frankly, how many people managed to find them there?
Another big but not quite noticeable change: autofill functionality will try to fill out user names if the page has no password fields. This should work well with most of the pages that split logins to two pages, or if you need to use "password reset" functionality.
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