I have the One, but recently upgraded to the fitbit HR. I loved the One! I never, ever had a problem with it! The battery life is great and it was perfect for me. The only reason I upgraded to the HR is because I have the need to track my heart rate all day so I would have a truer calories burned report.... and I didn't want to have 2 things to keep track of. I am like you, I wasn't sure I would be ok with something on my wrist, but I have had it 3 days and I am completely ok with it! It is light! I love, love love it!

If you don't mind moving the Fitbit from one piece of clothing to another, the One is a good choice. I had one until I forgot it was in my pocket and threw it in the wash (it did recover after 10 days). I now have a Charge HR and I love it. I like not having to move it when I change clothes and I really like having the heart rate function, but after 5 months, it still bothers me a little to have it on my wrist (I'm a Princess and the Pea sort and lots of things bother me).

The Charge HR does NOT have the battery life of the One. I doubt it would last for a full week. If I were going to need it to last longer than 3 days, I'd turn off the HR function for the duration. Those LEDs they use for measuring heart rate are bright and have got to take significant power.

I have a Charge HR , but I have been doing a LOT of reading and research and people say the ONE is much more accurate, as far as steps go, so if you don't need a wrist model, and don't mind moving it around, I would go for the one. The flex and charge track steps when you are doing arm moving activities. a little frustrating.

All Fitbits are great.

One pros: carries a long charge and is invisible.

One cons: easy to forget in the wash, no HR.

Flex pros: carries a long charge, waterproof, sleek looking, fashion options (colored replacement bands/jewelry)

Flex cons: clasp occasionally comes undone, no HR. All of my bands broke eventually- there is a structural weakness at the point where the lights shine through.

ChargeHR pros: tells time/date, exact step count, caller ID, automatically tracks sleep (and naps), heart rate (app gives graphs of everything including resting HR over time) and figures out calorie burn without needing any other input from you. Splashproof, rainproof. Buckle clasp stays on.

ChargeHr cons: No fashion option to change strap, somewhat bulky, needs to charge more often than Flex or One, wildly inaccurate stair count (which isn't used in the burn calculations, fortunately).

Charge: slightly less expensive than Charge HR but without the HR and a less secure clasp. I don't understand why anyone would buy this.

Fitbit now supports multiple trackers on one account. I wear my Flex for water activities, and if the Tori Burch Flex jewelry ever becomes affordable, I could see myself slipping my Flex into it for more dressy occasions. I also wear my Flex when I charge my ChargeHR. I wear the Charge HR all day and night unless I'm bathing or charging it. I've gotten used to wearing a "watch" again and I LOVE it.

NancyN795 wrote: »

I'd add one more con to the Flex: no display. If you want to know how many steps you've taken, how many calories you've burned, etc. you have to pull out your phone. When I was fist considering getting a Fitbit (back in late 2013) the lack of a display was the main reason I ruled out the Flex. Especially since the phone I had at that time wouldn't sync with a Fitbit.

Flex does have indicators in the form of flashing/glowing lights in the band. Tap the lights and one will glow for every 20% of goal reached. So if I walked 5,000 steps of a 10,000 goal, 2 will glow and one will flicker. I do prefer the digital step readout of the Charge HR.