Bests & Worsts Reviews from Amazon

I bought this product in May, when it first came out. It worked fine for about three months. I wore it 24/7, recorded my sleep and meals. It suddenly stopped working properly during the last firmware update. The wristband no long vibrates upon reaching a goal or an alarm; it will not sync to my Mac or my iPhone. I only get an error message saying the battery is low, but it is fully charged. Very disappointing. UPDATE: After my first FitBit Flex failed, I bought another during the summer. That unit has also failed now, just after Christmas. It appears these things last about four months. My idea of a strenuous workout is washing the car, so I cannot see how I wore it out or broke it. I wore it 24/7 to track my sleep, at work, on walks... and wore it in the shower (as it was clearly intended by the manufacturer). Yesterday, it just stopped working, like before. It will not take a charge, sync or anything. What a piece of junk! At $100 a pop, it looks like the yearly cost of using a FitBit is around $300. I cannot wait until Apple makes a wearable product to measure activity, etc. In the meantime, DON'T WASTE YOUR MONEY ON THIS!