He does speak with a lot of enthusiasm so I do believe he is sincere. I wouldn't call him fishy like other have. Yet, when you try to (pun intended) sex up Theology of the Body to make almost cool, hip and flashy, sometimes that doesn't really work. I think there is something to be said for a layperson trying to translate Pope JP II's writings as they don't really translate all the well into English. I have been to TOB discussion groups and there are passages that are very hard to understand. Yet, I think Christopher West can take it too far, which seems to either really put people off or really excite people.
The main issue that I have is when TOB gets mistaken a some kind of license for married couples to do whatever they feel like doing minus contraception. That clearly isn't the message of Pope John Paul II and whether it is intentional or not, that is message that can come across when you hear Christopher West speak.