It's always amazing how someone's "indispensible feature" is something that someone else couldn't care less about.

I don't even really use the concept of open files. I mostly switch files using a fuzzy finder that lists files in the git repo. So what files are "open" in my session is irrelevant to my workflow. (Unless they have unsaved changes of course, but I basically always just use "Save All" so even that state is minimal.)