Buzz was pretty great from a technological standpoint. I mean you can't argue otherwise if you dig Google+, because the stream from Google+ basically is Buzz. Works the exact same way. Muting posts, attaching links, uploading photos, commenting, editing, etc. are all from Buzz. Actually Google+ sharing is sort of a gimped Buzz because Buzz would let you import a bunch of posts from other services like Twitter, Flickr, etc. The closest Google+ gets is Picasa uploads, and it only does it for uploads from within Google+ itself.
It's a shame the privacy fiasco shot Buzz's kneecaps clean off, though. It was a lovely service to use. I myself had been using it from last summer until Google+ launched, it was pretty awesome if you followed the right people. But with these kind of sites, people they don't want to go out and find interesting people, they want all their friends they already know to find them. So it's sort of an inherent laziness, too. IMO the worst part about Buzz, technologically, was that you could only post from within Gmail. That severely hamstrung it after the privacy fiasco. Posts could be viewed outside of Gmail, and you could even comment on and like them. But you couldn't post from outside Gmail without a third-party client. And that is lame.