I'm very serious. I don't like Yao's game. He can do some things, but he's not a complete NBA player, and I don't think he ever will be.
Dalembert is more athletic, quicker and more coordinated. He has a decent outside touch and runs the floor better.
He doesn't score like Yao, but the Sixers aren't emphasizing that part of his game. They don't need him to be a 18 pt. scorer to be effective. (Although I think the Sixers would be better off making Sam more of the offense) Jim O'Brien has more talent on that team than he knows what to do with, and his unwillingness to establish a rotation hurts the players development.
As for trading Dalembert, who would the Sixers trade him for? Going by the same logic Joe used for Yao, a team would have to put together a decent deal for the Sixers to jump. They need a center, so any trade would require one, and logically since that center would be less capable than Dalembert, we'd need another player for compensation. .