Issues with using WebDAV as a back-end?

It has been suggested that a WebDAV back-end would be useful (WebDAV implementations range from self-hosted to internet-scale providers). There were many reasons why remoteStorage was written as a separate protocol, not least the variations in what features various implementations of WebDAV support, and their colorful variety of bugs, which often have gone years without fixes.

However, is there a lowest common denominator of WebDAV features that could be relied on? Is there a problematic impedance mismatch?