I tried most of the ones on the list. I'm currently using [Spark](https://sparkmailapp.com/) not as buggy as Airmail, mailbox many of the features I liked from both.
I've tried Spark too; I kind've slotted it under the "others" in the "needs Mac app" category. I didn't really feel it did anything better than EasilyDo Mail (which has more personal assistant type features) or Boxer (which is more customizable) if I was going to go for an app on iOS only.