So I've actually been transitioning my personal communications over to Protonmail (on a custom domain to future proof the address), and keeping Gmail for transactional emails (because of utility in Inbox grouping, Google Now, etc).

I've realized that I don't really care about Google having access to my transactional mail (things knowable from third parties anyways), but do want personal communications properly encrypted. Basically, I've only moved over my "priority inbox," and keep using Gmail for junk.

Very satisfied with Protonmail though. Especially knowing they are working on fixing their lock-in issues.