[dmckeon]

I've been using https://www.eff.org/https-everywhere since 2011 (Firefox 3.6 back then) and only rarely see sites that serve a default page or stall with https.

That's anecdata, but to get good data one would have to try to fetch & compare results from both protocols for many websites - perhaps Google or the Internet Archive has done this?

The biggest annoyance for me in using https preferentially is that I often end up with multiple bookmarks for the "same" page, which differ only in their protocol - it would be nice if there were an auto-magic way to upgrade the old http bookmark to the https protocol.

[Noctem]

That's because HTTPS Everywhere doesn't blindly attempt HTTPS connections, it redirects based on a massive set of rules. That's also how it accounts for more complex changes than just the protocol portion of the URL, like adding an encrypyted. or ssl. subdomain.

You can see all the rulesets here: https://gitweb.torproject.org/https-everywhere.git/tree/src/...