Because other products report the same complaints as Devonthink users, I’m inclined to think Apple could do a better job.
Dropbox is not a solution for personal information. I don’t write or store anything that would embarrass my Mom, get me in trouble in court, or even irritate friends with irritating habits.
Which doesn’t matter. My thoughts are private while within my skull - at least for the moment - and when transferred to files should also remain private.
Dropbox once left all their accounts open for login without checking passwords for a few hours. They have my sympathies, but not any data I don’t consider published.
Best solution for me is leave the iPad at home and carry a Macbook. Sync via encrypted thumbdrive. Yeah, yeah, I know. They fail. It’s not a backup device.