Bill Martens just wrote a very nice review about Mailplane 2.0. He's a longtime Mailplane user, and just upgraded from 1.61.7 to the new 2.0 version. He talks about his experiences and about which features he likes most. A great read!
Once restarted, the application came up and showed an email with a list of all of the new features included in the application. This allowed me to easily go through the feature list and see if there were any in particular that enthralled me. One such feature was the new Attach Folder and File Bundles feature in composing emails. No more clunky single file attachment nightmares. Now it can be performed in a single swoop.
Mailplane got a 4 out 5 "Apples" rating.