My personal advice is to use this as it links up with Myfitnesspal.
I have found that without a doubt myfitnesspal has the most complete database of foods, the account and the phone app are both free, the phone app has a bar code scanner you can use for packaged foods, and it's incredibly easy to use.
Entering your data (IE food and certain activities) into myfitnesspal automatically imports into fitbit so that you can use the features of both sites without having to enter the data twice.
- Links with myfitnesspal and adjusts your calories up or down based on actual activity. Without this MFP has to estimate your calories burned based on what activity level you told it upon set up. Some days you're more active than others and with negative calorie adjustments enabled it ensures you move enough to get the calories allotted. A definite bonus if you're sticking to the calorie target and you're still on a plateau.
- Phone app gives you easy access to calories in and out, without myfitnesspal you can enter calories into the phone app, as well as track other activities (such as spinning which also doesn't register very well)
- Sleep tracker identifies how restless you are in your sleep. It's not the best sleep tracker but the sleep efficiency can be a very good tool for you to see how much better you sleep when you've exercised. If your sleep efficiency is terrible, see your health care provider about a sleep study.
- It's waterproof and although I haven't actually sent mine through the laundry I hear from friends it survives.
- The phone app doesn't have a bar code scanner. However, if you use myfitnesspal this is irrelevant.
- It's small and can be lost, so be careful. The Flex is worn like a watch and less likely to be forgotten or lost but I haven't tried this device.
- It shows you your activity, it doesn't burn calories for you, you WILL have to get off the couch to actually move.
- While I hear it syncs with many phones, too many devices are unsupported. It syncs with the iphone and a very select few androids. It would be nice to be able to sync while out and about.