> Its syncing mechanism is absolutely bulletproof and [...]
Hate to have to say this, but no, it isn't.
If you use Simplenote with multiple devices, especially if you use some of them only every few weeks or months in a no-reliable-internet situation or as a pinned tab in your browsers, it is the opposite of bulletproof. You have to deal with overwritten notes by much older versions and no indication it happened.
(Yes, I reported this multiple times but never heard back. Shame, because besides this I also really love Simplenote.)
I use simplenote on 2 iOS, 1 android, 2 windows, and 1 linux and have never had the problem you're describing. None of them have intermittent connectivity, though.
Thing is, since all the notes are backed-up as simple textfiles to Dropbox and Dropbox saves history, even if that does happen you'll never be screwed over by it.
Dropbox backup is a belt+suspenders type deal. Simplenote also saves full history; I just checked my version of "ToDo" (named "Misc Apartments" for reasons you can probably guess but aren't worth going into right now) and it has full history for every single edit going back 212 days inside Simplenote's web UI.
Hmm, is Dropbox backup still available? I have two accounts, one that is still premium from when this was available and have the Dropbox backup option, but it still only backs up when I hit the button. On the new one, Dropbox backup doesn'T seem to be available :(
The simplenote client I use on windows, Resophnotes, backs up to Dropbox. I know they used to charge for that functionality before they were bought-out, so not sure how to do it on other platforms.
Hate to have to say this, but no, it isn't.
If you use Simplenote with multiple devices, especially if you use some of them only every few weeks or months in a no-reliable-internet situation or as a pinned tab in your browsers, it is the opposite of bulletproof. You have to deal with overwritten notes by much older versions and no indication it happened.
(Yes, I reported this multiple times but never heard back. Shame, because besides this I also really love Simplenote.)