I don't think I would... at least until the kids are in junior high.
I've researched a lot about violence and the media, and I do think that a lot of concerns about it are overblown. But that said, I just don't see the need for elementary school kids to watch that stuff. We'll probably have the kids do a martial art though. RL FTW.
Will you (or do you) let your kids watch UFC, WWE or boxing?