I've been reading this thread with a growing sense of foreboding, which has in turn created a growing rage, and finally, resignation (literally).
I've been using EN since 2008 on Mac, Windows and iOS - but mainly on a Mac. It's never been been feature-level across all platforms but has been a joy to use - until now. I have a very slick (IMHO) GTD workflow that works for me. It involves using tags and only really works because I can see a lot of information on a small screen.
The release of 10 has blown that out of the water because of a UI designed for 5yr-olds and loss of features. I've only just noticed because I got a new Mac and was landed with 10.5.7. I've downloaded the legacy app for now, but the clock is ticking.
Some years ago I moved all my non-GTD notes to OneNote because of some other inane design decision (I got fed up with the awful text editor), but EN has been a great GTD app. However, now I've taken the decision to migrate before my plus subscription expires next month and have cancelled the auto-renewal.
During the downgrade, I was asked to give my reasons. They were simple "I've lost too much productivity developing work-arounds for the poor design decisions and implentation in V 10. Basically, don't trust you with my data anymore"
I've started to review alternatives. All I need is a very good GTD app. Even if it means I have to-key, I won't loose as much as I have with V 10. I've looked at DevonThink before. It's good, but Mac-only which is no good. I'm about to look at Joplin.