Flock is based on the Mozilla browser and in some ways feels like Firefox. I've uploaded only a couple of extensions for Flock (there aren't that many available as it's still relatively new), unlike my Firefox browser which has several installed, yet there is a discernible hiccup to the Flock browser compared to Firefox when scrolling down pages.
Blogging, on the other hand, is definitely easier. It posts quickly, it's easy to attach links and mark up text, adding images ain't too difficult (though you have to watch that Flickr HTML as just dragging and dropping doesn't add the HTML code Flickr prefers external websites to use -- update after posting reveals images are still a pain...will have to figure it out later), and it works without annoying error codes popping up. Tags are a bit of a pain as it doesn't give you a pop-up list of labels already created in Blogger. But on the whole, it's much better than the traditional method. So, for now, I'll go back to Firefox, but use Flock for blogging.
Blogged with Flock