It's clean, it's fast, and it looks beautiful. And it blocks trackers and doesn't keep history.Cons:
It's not that fully-featured and is really only good for the ocassional browse.
Firefox Focus is a great mobile browser to use when you don't want to be tracked or you just want the web page you're looking for fast, without all the extra bloat. However, since it doesn't keep history, it's not great for normal browsing, unless you're fine with forgetting by default.