I'm curious how others are doing comparison analysis of campaigns, specifically comparing open times over time between different emails. Allow me to provide an example:

I am sending a monthly email to a group, each time we are adjusting format, and deployment time slightly. I would like to compare how those adjustments not only change the engagement time but also change how soon the email is opened after deployment. Did most open it within the hour, 2hrs, the next day, etc.

Open timestamps exist within the detailed exportable data and a report could be built out of this, but I would think such a time graph would be a default report view. How are you analyzing this?