I have yet to find the person who, being comfortable with both raw SQL and a particular ORM, to, when faced with the choice of learning a new ORM or using raw SQL, reach for the new ORM. To be honest, I haven't met in person anyone who reached for the familiar ORM, either, for anything complex in a team environment, but that's a more aggressive statement.

I mention this because to my mind it reinforces my belief that learning an ORM (which I've done in the past, and then never used again) isn't worth the effort; learning SQL is, if for no other reason than it's portable (and you'll have to learn it anyway when the ORM's abstraction leaks).