Look elsewhere if you want to keep your data stored locally. – OmniFocus 2 Review

Omni offers cloud syncing your data. If you want to store your data local, they provide instructions, but no support for WebDAV. My WebDAV is broken. I tried calling and emailing. Omni says “sorry - we do not provide support for WEBDAV - we provide support our encrypted cloud server”. If you want to keep your data locally - look for another solution.
Review by TType on OmniFocus 2.