I am incredibly lucky to have two Fitbits the Fitbit flex 2 and the Fitbit charge 2.
I would highly recommend both Fitbit’s they both have their positives and I use both of them equally.
The Fitbit charge 2 is used when I participate in my dance classes as it records more detailed information on my heart rate for example fat burn, cardio and peak and how many minutes of each. It can also detect what sort of activity I am doing for example aerobic, walking, cycling. I love how the charge 2 tells you if you have a text message, phone call, calendar events. It also records your active minutes. The charge 2 records the different stages of sleep which is really useful.
While the Fitbit flex 2 does not offer the heart rate options it is a slim and offers the steps, distance, calories and sleep but not as detailed as the charge 2. It is great option for me as it is discreet. I wear this one for work as its smaller and no screen so no chance it will get scratched. When I can’t wear this on my wrist at work I use a go travel body wallet.
Go travel body wallet https://amzn.to/2GZBCtq
Fitbit charge 2 https://amzn.to/2GpxfuE
Fitbit flex 2 https://amzn.to/2pSXbUg