I have the version from extras testing, and would like to say I love it. It's a little bit slower than mauku in my experience, and I've had it lock up a couple of times (and crash out 'not responding'). But the increased functionality is awsome and makes for a much better experience.
The thing that seems to annoy it is when I tweet or reply and I hit 'tweet' just as it was doing something else (like auto refresh). The result is the screen freezes (and I keep hitting 'tweet' cos I'm an impatient little beggar). Then I discover that the tweet has in fact gone through when it appears on tweetdeck on another pc. Don't know if this feedback is any use. Thank you for doing this - I can see Witter becoming the most useful twitter app on maemo.