Fitbit's One is arguably one of the best activity trackers available today and, yet, less than seven months since it hit the street, Fitbit has decided that a stripped down version worn on the wrist was something the market's been clamoring for. Back in '77, Bert Lance first uttered the immortal phrase "If it ain't broke, don't fix it." There's a reason we still say it today.
The Flex is a paradox in that it fixes a handful of gripes users have had with the One but also manages to completely shit the bed. It's quite the conundrum.
With the popularity of the Nike FuelBand and, to a lesser extent, the Jawbone UP, it's no surprise that Fitbit opted to fast-track a similar device. When you've cornered a market for the better part of the last four years, what do you do when companies with more money start shaking you down? In this case, apparently, you start copying them.
Fitbit's One is far less sexy and much, much dorkier than its direct competition. Mainly because it's meant to be clipped onto your belt, bra or shoved into a pocket. And for some reason, people tend to lose them pretty frequently. The Flex overcomes that dorkiness, but loses a few features in the process.
It still counts your steps and analyzes your sleep, but it can no longer tell when you've gone up a flight of stairs. Nor can it convey any information, like the time, directly to you from the device. You're now relegated (or forced into?) to use your smartphone, assuming you have an iOS or Android device, to see what's actually happening. Fitbit sacrificed both the display and the altimeter sensor from the One to make it more of a wearable, which has its pros and cons.
A series of five tiny LEDs are now the only visible cue as to whether you're getting close to reaching your goal for the day (there's a default, but you can also set your own goals online or through the app). To check your progress, you tap the top of the Flex twice. When you've reached your goal, the Flex lights up and buzzes. Aside from the occasional twinkle of its LEDs, the Flex basically looks like a thin black bangle or charity/organization bracelet. It's so minimalist and unassuming that I can't get myself to say that it's ugly. It's just... there. The clasp, for better or worse, makes it obnoxiously secure on your wrist and there's no risk of ever losing it the way you might lose the One or the cap of the UP.
Unlike the One, you can never really forget the Flex since it's on your wrist and is waterproof, and depending on how active you are, need only be charged every five to 10 days, though it can go longer. Like the FuelBand or One, the Flex syncs over Bluetooth to either your computer via a USB dongle or to your iPhone or Android device. You can even transfer data over NFC, if your Android device supports that sort of wizardry. The accompanying app remains the same from previous versions but the desktop site has been revamped for a more visually stimulating experience. (Yeah, it looks a little bit like Nike's Plus portal.)
Based on prior research and testing nearly every single popular activity tracker (Nike FuelBand, Fitbit One, Larklife, Striiv Play, Jawbone UP, Basis B1, BodyMedia FIT) available over the last year, I compared the One versus the Flex as the former most accurately tracks the number of steps taken—the core function of bi-pedal tracking devices. This is important to note because the One takes into account the number of stairs climbed to calculate calories burned, and the Flex has done away with the altimeter. The whole point of these devices is to help quantify some semblance of your overall health. Sleep analysis is something that doesn't factor into my evaluations of these types of activity trackers because I've found them to be inaccurate for a number of reasons. Some people just suck at sleeping, like me, or you just twitch a lot, which any device with a 3-axis accelerometer will interpret as an interruption in sleep. (To activate sleep mode on the Flex, you tap the device five or so times and the same to wake it up.)
Looking at the numbers (steps, distance, calories burned), this is how the Flex compared to the One:
Over the course of four days, the number of steps tracked on the Flex versus the One varied from as little as a few hundred to several thousand. Oddly enough, on days that I work out, like Day 3, the Flex's numbers are more inline with that of the One, than on days when I don't go to the gym. Which is the exact opposite of what I thought would happen. I received the Flex during the middle of Day 1, which is why distance and calories burned were thrown out.
Well, the Flex is finally a wearable in the sense that you don't have to fret over its whereabouts, battery life is quite good and for its lack of pizazz, it can pretty much go with any outfit. There's also a wealth of third party apps that you can tie into your Fitbit account for more data crunching, like Run Keeper, My Fitness Pal and Lose It!.
There's no display or altimeter, and the silent alarm function still hasn't been modified for use as an idle alert like on the Jawbone UP. And based on the numbers, it's not as accurate as its predecessor and is less motivating because of its minimalism. The tiny window in which the LEDs shine through on the band itself are susceptible to the tiniest of scratches, too. While there's no tip to lose like with the UP, if you lose the Flex's charger, you're SOL until you can get a replacement. The USB dongle could also be easily misplaced but at least you can sync over Bluetooth to a mobile device.
Priced at $100, the same as the more full-featured One, I don't know why anyone would want to buy the Flex. It's inaccurate, has fewer features and is the least motivating activity tracker of those available today. To be honest though, if you're relying on a device or app to get you moving, then you've got a whole different set of issues to contend with. If a friend were to ask which activity tracker they should buy, I'd recommend the One or Basis B1 before the Flex.