Browser is a Browser. A browser with WebKit inside - thus there is no need to tell you about the browsing experience. There's simply is no better way to surf the web.
So - why another one? Because browsing should be about finding - not searching. Finding websites, content, bookmarks and pages stored for reading later.
Tag it, baby! Tired of searching for bookmarks? Need your brain for more important tasks than remembering URLs? That's why Browser allows to tag bookmarks and directly open them by simply searching for such a tag. And because sometimes a tag isn't enough - Browser also allows to make use of comments.
Drobox. Enabled All bookmarks, all pages stored for later reading are automatically available on all your Macs. Incl. all your tags and comments.
History. Repeating. But wouldn't it be great to actually have the complete history on all Macs available as well? Guess what.
12345. Fail. And because we all use such risky passwords, Browser will store secure ones for you. And you only have to remember a single one.