Charles, thanks for your work on this release and for your very receptive ear.
My 2 cents ...
I like the layouts in this order:
1) Portrait with AR
2) Square with AR
3) Portrait no AR
4) Square no AR (this is the worst!)
I agree with Dr. Ohh that a darker gray shade would be preferable. Perhaps something closer to the shade used for the library shelves in Moon+ or what's already used in the menu bar of CC?
--Pat