If you're using 1Password for Mac or iOS, then simultaneous writes are a non-issue. All sync types have conflict resolution implemented, where worst case scenar

If you're using 1Password for Mac or iOS, then simultaneous writes are a non-issue. All sync types have conflict resolution implemented, where worst case scenario it'll put the overwritten password into a "Conflict" section at the bottom of the item. With the other apps, you'd get nice behavior with 1Password.com because the first one to hit the server will have its record saved in the archive. That's one of the nice features of 1Password.com, getting to see item history. You don't need to worry about accidentally overwriting changes.