With all the respect towards Paladins, lately I've realized that:

Ninjas > Paladins in tanking. Of course it depends what you tank - for example Ninja's really own mobs that hit very hard. Surely they are screwed against monk type mobs, but generally past 70+ there's a lot more love for ninja than Paladin. I love them both though, but I myself like good ninja a lot more than a good pld. That's why I'm taking ninja up now.