I think it is unfair to hold the Iconfactory guys to a bar set by Twitter.app — built by the service’s in-house developr and released very late in Twitterrific 4.0’s development cycle. That said, I think Ben’s done a good job at listing the app’s shortcomings.
Twitteriffic — on all platforms — is a complex app. Craig Hockenberry and his team give users more than one way to do things. I think most of these will get resolved quickly — the Iconfactory has always been very quick to fix things. Besides, most of what Ben doesn’t like could be solved by giving the users more options — the very thing the developer is prone to do.
I’m using the app both on my iPhone and on my Macs, and am quite happy. I think Twitterrific 4 has some ground to make up, but I really like where it’s headed.