I think one of the problems with iOS sync is that it is often unclear whether things have synced or not. A small indicator at the top of the screen, like the old “dirty” file icon that would show in Mac OS when there were unsaved changes would help this a lot. As would the ability to pull down at the top of a document to force refresh/sync.
More than that, I find between PC and phone, I might make changes and I know those changes have not yet synced (not here yet) but the words at the top say “Synced”. I think the program simply hasn’t checked in a while so it doesn’t know it’s out of date, but this is an important thing for me to know before I start editing.
I guess there’s a difference between “all the stuff you wrote is sent” (synced) and "all changes other people sent to the server have been received (no indicator exists).