Moving things is not reliable. Often when the app is reopened things are back when they should have been filed. Oh, and gosh forbid you undo moving a thread...
Ill stick with Mail until there is something better...
Should also mention that interactions with support mostly resulted in "no error on our end" responses. Sorry devs, I really would not waste my time reporting things unless I wanted to help improve your app by reporting real issues. But apparently you know everything and my feedback is not welcome.
Hbax450 about Airmail - Your Mail With You, v1.1