I'm not anticipating a chance to play with the NG driver soon; my queue's already dropping.

Regarding the conceptual mismatch--you're absolutely right that that's the case, but one of the reasons I like the current behavior is that I use the same entities with both PostgreSQL and H2 (for testing). Using a non-DB-specific configuration that gets translated to something that looks like a standard string on the database's end means that Hibernate is essentially agnostic as to the implementation detail of how the column is being stored. While I certainly understand the ontological appeal of using UDTs, I'm concerned that that would break transparent backend compatibility.