Obviously with it being Alpha, there are a quite a few bugs, and upon launching the app I already have found some. So be warned!
Also UI animations won't be that smooth, notifications aren't available yet, features from the iPhone and iPad version aren't in the app and a ton more of stuff has still got work. So the official version of the app may be a while away.
This is definitely a great start though and the app is beautiful, using the dark grey with neon blue accents, it's gorgeous.
There aren't many major new features which would make you pick it over the official Twitter client but hardcore TapBots fans I'm sure will still use it.
If you find a bug please help the developers out and report them here!