I have the Ultra Fitbit. So my question to you is what do you want it to measure? What do you want it to do? Do you think that it will help you if you knew those measurements? how much do you want to spend? i know the body media is much more expensive than the fitbit.
i love my fitbit. I love the petals i achieve after a rigorous workout. I love that it is tiny and no one has to know I am counting steps, stairs, sleep patterns and calorie burns. Is it worth it? Sure. I love mine.