I've been using a variety of Doge RDA's for a while. They have some pretty beefy airflow, and the deck size allows for some pretty large builds. I own 3 Doges, varying versions, and I've been satisfied with all of 'em.
I've heard reports of spinning center posts and melted insulators, but that's usually in cases where people are trying to jam crazy .08 ohm clapton-type coils in there.