Airmail2 is my desktop client of choice for Gmail. It keeps the same hotkeys as the web version of gmail and has some good integrations.
In outlook, I use
^O to send an email to Omnifocus. That workflow also attaches the outlook email to the task for easy reference later. I wanted something similar for gmail besides just forwarding the email to Omnifocus. With that, I still had to go find the email to actually reply to it. Omnifocus integration is the single most important reason (to me) for using Airmail. Airmail will add an in-app link back to the email in Airmail in the notes section of the task.
But, I don’t like the default hotkey, I just want it to be
^O. To get this to work: