Like previous versions, the Apple Watch Series 4 offers the best combination of style, message handling, app selection, battery life, and activity tracking of any smartwatch for any platform. With two size options, the Apple Watch is also one of the few smartwatches that look good on even the smallest wrists. But the Series 4 models—available in 40 mm and 44 mm sizes—offer larger screens in bodies that are roughly the same height and width as last year’s versions (though slightly thinner). The Series 4 is also noticeably faster than the Series 3, Siri is more reliable, and details (such as the improved Digital Crown with haptic feedback and special watch faces that fit more information onto the new display) further improve the experience. Upcoming arrhythmia-detection and ECG features are bonuses that, according to Apple, may be useful in detecting some heart conditions.
The Apple Watch Nike+ is identical to the aluminum Series 4 but has Nike+ watch faces designed to be easier to view while you’re exercising, along with different sport-focused band options.