With the price in the $100+, I obsessively consumed the billions of reviews and comparisons between the products. I ended up going with the FitBit Flex for its price and the fact that I can safely wear it while swimming (the other 2 being totally not waterproof).
It served its purpose, I was more motivated and used it religiously to track my daily sleep, calorie intake and activities (steps). Obviously, it takes more than a tracker to achieve fitness but it definitely helps.
Word of caution, charging unit requires a proprietary cable and the process is a hit or miss (try googling “fitbit flex not charging”). Also, 3 months in, the strap kinda broke;
So there’s that. If you are considering one, maybe hold off the purchase for awhile. The products are nice and shiny but probably not ready for primetime yet.