Flock is the browser for people who love features but hate plug-ins and extensions. There's very little you can do in the product that you can't also do by layering extensions to your Firefox installation, but in Flock they're all preconfigured and integrated into the browsing experience. With the latest 2.0 release of the product, Flock now gets the current Mozilla engine (the same one in Firefox 3) as well as a few additional media and social net integration features.
I was a big fan of Flock 1 before Firefox 3 and Chrome shipped. I found it more stable than my Firefox 2 installation, probably because I had Firefox loaded down with extensions. And it did more than IE 7. But with the speed and stability of Firefox 3, the decision to use Flock is now about the features.
Flock does a lot for a browser. It integrates social media feeds from MySpace (which is new to version 2), Twitter, Facebook, and other sites. You can see everything that is happening with your friends, across all your networks, in the sidebar. You can also view media (photos and videos) from media and social sites like Revver (new), YouTube, Flickr, Facebook, and so on. The media view is entertaining if you set the filter to "my friends."
Like current browsers, Flock recognizes when a page you're on has an RSS feed, and gives you the capability to subscribe to it. New in version 2: It can also subscribe to media streams and display the items in the media bar.
If you close down the media and social sidebars, Flock feels a lot like Firefox 3, down to implementation of the "awesome bar" URL entry field. You can even add most Firefox extensions to Flock.
But the best way to use Flock is to immerse yourself in the river of social updates it will feed your way. New users will likely find it overwhelming at first, but the product really does give you a more comprehensive and real-time view into your social network than you can get otherwise.