Had a conversation with Savva. He persuaded me in the value of using a separate root table per subclass in cases of vertical inheritance, as opposed to using common root table across the entire inheritance hierarchy. With such change, model becomes more explicit, mapping can be done faster, syncing with DbEntities won't be an issue, etc. I.e. while runtime functionality stays the same, it enhances user experience. Will need to find time to make this happen. Perhaps people would start using it again.
Andrus