Gavin King (the hibernate guy) is writing about SFSB. While not everything he wrote is correct (according to the comments, which I did not verify), his last sentence Lesson: beware J2EE folklore! is completely true.
I often hear "CMP is useless". When you ask people why, they tell you some myths or results from a foaf or things they experienced years ago, which is not true on a modern CMP 2.x server like JBoss.