I have settled on Google Keep for my note-taking, for ease of use and durability. I like that Standard Notes is similar, but adds privacy and the option for self-hosting. Being open source and extensible is a bonus!
Also, the UI on desktop is pretty poor. A native mac app would be a huge boost.
It's a shame there is no public Keep API to play with. I would write the app myself!
Some of the features I like about it:
Searchable
Formatting support
Edit history
Android App
Good web interface
Syncs perfectly between platforms with simultaneous editing
Google is unlikely to disappear with my data anytime soon, and has been good about letting you take your data with Google Takeout
And some things I don't like: My own Cloud/NSA paranoia
no end-to-end encryption AFAIK
Android app sometimes slow to open a note for editing