I had wanted something like this for awhile and, having done some research online, I decided the FitBit Charge would be best for me in my budget. I have had it for over a month now and I absolutely love it. I like being able to see how many steps I have taken in a day, and to see the calories I have burnt off but overall my favourite aspects are the sleep monitor, which has really helped me see how badly I sleep (that's having children for you) and the call alert. This function allows me to see that my phone is ringing, along with who it is calling me, even when my phone is on silent or in my bag. This has been really helpful as I am job hunting, so I don't miss important calls from recruitment agents or employers.
Overall I think the FitBit is fantastic. I haven't used it to its full potential yet I feel, but I can see that it is helping me to be more active and motivated to lose weight and tone up. Ed is getting the FitBit Charge HR for his birthday at the end of this month, so I hope we can use them together.