Hi. Just for information:
I, too, updated AquaMail a week ago and was upset with the new design. I immediately downgraded from a Titanium Backup. Today I took some screenshots of the 1.7 app and then updated Aquamail again and compared the actual new design to the old one. Most of the issues I had with the new one was fixable.
Yes, the checkboxes are there instead of checkmarks - I noticed and thought "there were no checkmarks in the old design" but hey I was wrong. It's a subtle change and you notice and get angry because you were used to the old design.
The checkboxes can be removed completely with the newest developer build, see
Version 1.8.2-201 - "stable hotfix", not in Play yet.
I then enabled grouping by date, slim fit, floating action button, floating action bar and enabled swipe (for "move to SPAM" since it's now hidden behind another click on the three dots in the floating action bar (see
Feedback on design refresh in 1.8)), changed colors and it's almost as the old design.
Did I like the new design at first? Hell, no. Sure, it's new and some things changed, but I'll get used to that. AquaMail is still by far the best email app compared to other apps like K9.
I think you're making a mistake by moving away. I bet you'll get it to almost 100% of the old functionality of your workflow in less than an hour of customizing the settings.