I also carry a ton of critical information in notes. I've tried extensively Apple's iCloud-synced notes, Evernote, and Microsoft's OneNote. Apple is poor at solving trivial conflicts. Evernote is even worse, and really unreliable. Microsoft OneNote is great at reliability and syncing (UX is so-so in mobile, that's the only gotcha). I wouldn't have expected so, but they have the upper hand here.