Embracing SQL in Postgres
I'm sure anyone can come up with specific situations where writing SQL is much better than using ORM.  
If I had infinite time and dev resources I would never use an ORM.  In reality Entity Framework makes abstracting my data-layer very easy and increases my productivity.  It also makes me feel much more comfortable about switching databases if necessary. Even if I'm taking a 5% performance hit it is totally worth it to me.