All kinds of things have been fixed since beta1. Even more things remain broken. If you are happy on beta1, I would avoid upgrading, because it will be a gigantic pain and you won't get much out of it. In fact you might be better off just reinstalling (which is fine, because you can regenerate past activity, but you'll need to recreate any custom rules).
That said, if you're installing for the first time, use this. I tagged this release so people could stop using the dev build, since there really haven't been any new developments for a long time.
