I dont necessarily understand some of the more negative reviews of both the fitness tracker or the app. The Moov devices, in my opinion, do exactly what they were advertised to do. So far I have tested running, cycling, boxing, and the body workout routines, all of which work great. Sleep tracking is close to being accurate, but not quite perfect; and without a heart rate monitor or skin temperature sensor I doubt its going to get any better. It simply gets a good estimate, which is fine by me.
I really like the Moov Now for what it is, a coach, and a great one at that. It forces me to push myself just a little harder than I normally would. It corrects my form when I start feeling tired on a long run. It motivates me to stay active by constantly reminding me in the app to get at least 30 active minutes every day.
So why only four stars? There are no social features as of now. I bought one for both myself and my parents so we could keep each other motivated to keep doing better (were all fairly active people with competitive personalities). Also, I would LOVE the ability to export GPS and fitness data to third party apps/sites such as Endomondo. I like having a centralized hub that keeps track of all my workouts (since the Moov app doesnt necessarily track all of them).
Overall though, its a great device with a very streamlined app that had a nice user interface. I imagine it will only get better from here.