i have found that i cannot get back to the basic view which i prefer, if the newer one has already displayed.
that is why i have to be quick and know where i am aiming for at the foot of the page, while the big M is forming.
if i get the newer one, i open a new window and search again for gmail inbox, which is usually one of the suggested options, as i keep my gmail open.
i know this might sound silly to some, but i can only cope within my limits, which are quite limited.
and actually it seems simpler to me than looking for other lines, settings etc, with which i am not familiar.
i am always a bit worried if i click on something i don't understand, as to what effect it may have.