I've been using DAVDroid since January to sync with my OwnCloud CalDAV/CardDAV server, and it's been working flawlessly for me. Every update in either directio

I've been using DAVDroid since January to sync with my OwnCloud CalDAV/CardDAV server, and it's been working flawlessly for me. Every update in either direction has synced without a hiccup. Most of the issues I've experienced have been relatively minor, and have been the result of issues with the Android platform itself, and not DAVDroid: there's no to-do/task list integrated with the default Android calendar app, so tasks stored in CalDAV don't show up without a separate app, and most of third-party to-do list apps for Android seem to either have significant flaws in their own right, or use their own proprietary sync protocols rather than CalDAV. Additional, Android's contact list doesn't have exactly the same layout of fields as the CardDAV standard, so there are a couple of situations in which certain data hasn't synced properly. But, again, these issues have nothing to do with the DAVDroid app itself, which is excellent.