The Xiaomi Mi Band 4 delivers fantastic value and features. Upgrades over its predecessor include a color OLED display with significantly improved outdoor viewability and a higher resolution too.

Very cheap; Slimline design; Heart rate monitor

No GPS; No multitasking apps; Doesn't auto-stop tracking

The Xiaomi Mi Band 4 now sports a 0.95-inch display with 120×240 pixels resolution. It also sports a 135mAh battery along with a similar 20-day battery backup claim. For connectivity, Xiaomi has added Bluetooth 5 in the new version of the fitness band.

In the world of activity trackers, nothing comes close to the Mi Band's value. Cheaper than any Garmin or Fitbit tracker, even the most basic vivofit4 and Inspire , but still packing enough functionality, it also benefits from Xiaomi's name recognition and is considered a serious choice, not a cheap...

Price $30-40 is cheap for what you get; Extremely cheap, Display It's bright, visible outdoors, beautiful, and doesn't affect battery life much, Battery life Even with auto-wake and heart rate measures every 30 minutes, plus some walks and swims, I can get about 10 days on a single charge, Google...

Interface It's not as customizable as I'd like; You can't reorder or hide exercise types, or remove unnecessary items from the More menu, Android app Clunky and shows ads; It's sad that you get ads even after having purchased the band, Swim tracking Worked well for the first two swims, then became...

At $40, should you buy the Xiaomi Mi Band 4 or pay double that for a comparable device from a competitor...

Low price point Accurate fitness; health; and sleep tracking Connected GPS is a big plus 20-day battery life Plenty of smart features and customization options

Mi Fit app won't be everyone's first fitness app choice Heart rate sensor struggles with high-intensity workouts

The below image seems to show that the Xiaomi Mi Band 4 will have a 0.95-inch full colour OLED display, with a tempered glass cover rather than plastic. This is a big improvement from the monochrome display of previous devices in the range, and should make it far more attractive to use - but we...