The Charge 3's module weighs in at 20 percent lighter than that of the Charge 2, so it won't weigh down your wrist when you're wearing it. I barely noticed it on my wrist when I paired it with Fitbit's woven bands, which are made of a feather-light fabric material. If you're looking for the band that both complements the device's weightlessness and remains fashionably flexible enough to go from the gym to the office, I'd go with a woven option instead of the standard silicone one.
Inside the Charge 3 are an accelerometer, gyroscope, optical heart rate monitor, and an SpO2 sensor for tracking blood oxygen levels. The Charge 3 is the third Fitbit device to include an SpO2 sensor, following in the footsteps of both the Fitbit Ionic and the Versa smartwatches. However, currently the SpO2 monitor lies dormant inside all of these devices as Fitbit hasn't made use of it yet.
When we compared the storage space of the Samsung Gear Sport with the other contenders, it didn’t have the most. With 4 GB — only a quarter of what you’ll get with the Apple Watch Series 3 GPS — you will have to manage your apps so you don’t run out of room. If you like to carry all of your music with you and you have an extensive library, you might run out of space with the Gear Sport.
While you're not getting Spotify or Apple Music here, you are getting enough storage for 500 songs with a process that's fairly easy. You just boot up Garmin Express, select the Music tab and choose which of your own music you want to port over. If you do want to sync over playlists from a streaming service, your only options are iHeartRadio and Deezer.
Bottom line: Some fitness trackers work equally well with an iPhone or Android device, but some smartwatches are built to pair with Android phones so you won’t enjoy full functionality and pairing on an iPhone. The Apple Watch only pairs with the iPhone so is off limits to Android users. Your existing phone choice will play an important part in choosing a smartwatch. You can check your smartphone’s compatibility with a range of Google Wear-powered smartwatches at g.co/WearCheck
The company claims that the SpO2 monitor will help its devices look for signs of sleep apnea and other breathing problems, potentially great features for devices that are meant to be worn 24/7. It'll be used primarily in Fitbit's forthcoming Sleep Score Beta, which further analyzes sleep quality using heart rate and breathing data. Starting sometime this November, users with devices that only have heart rate monitors can get a "sleep score" after each night's sleep. Those with an Ionic, Versa, or Charge 3 will presumably have better data thanks to the SpO2 monitor collecting breathing data.
No other smartwatch offers this much variety and customization, especially when it comes to female-friendly options. The Apple Watch is the only smartwatch I've ever worn regularly each day for months on end. I've reviewed dozens of WearOS watches, and although many of them are nice looking as well, they're not as fully featured or easy to use as the Apple Watch.
For deeper integration with your Android phone, you can give Google's Wear OS platform a try with Fossil's $275 Q Control touchscreen smartwatch. It lacks GPS and support for NFC payments, which is why the Gear Sport is a better fitness-focused smartwatch for Android users, but Fossil's Google Assistant integration and stylish design make it a solid contender. However, smartwatches with Qualcomm's new Snapdragon Wear 3100 processor start shipping in October, so you may want to hold off until we put them to the test.