Frustrating a bit...
It feels slow on rMBP (animations/resize)… Tweet input box do not resizes and do not moves on screen, a lot of small but nasty UI failures (when window is docked to right of screen - new tweet box overflows screen to the right, detached mentions columns has light-blue background over all tweets unline other columns, when new tweet box is opened there is no visual way to determine that background is disabled until tweet input box will be closed), previews window do not stores it’s location.
Do not worth it’s money by now.
Lambdy about Tweetbot for Twitter, v1.4.1