Ben Brooks' review of Twitterrific 4 finishes with this little comment.
It doesn’t feel finished — it feels like a version 1.0 product. If this was a version 1.0 then I would be excited for its future, but given the version 4 nature I am hardly impressed.
A fair assessment, but essentially this is a version 1. It's so different to the previous versions and I believe that the Iconfactory actually started again like they did on iOS with the new version. Still, some of the decisions they've made are odd.
As a side note:
You can’t close image windows (Twitpic and the like) with the keyboard.
Try pressing escape and you'll find this comment incorrect. I was being driven mad until I stumbled across this though, so I can see where Ben is coming from.