How good is the offline support?

Edit: After testing, seems not too bad. Reconciles non-conflicting edits just fine. But apparently, in the iOS app, search doesn't work in offline mode!

Edit 2: It seems like "attachments" (files like PDFs, and also images) are not stored offline, either. In the iOS app, clicking on a file or image brings up an S3 URL inside an embedded web browser.