The Apple Watch Series 6 is the best smartwatch on the market for an iPhone. It has better integration with the iPhone and is fast, fluid and responsive in a way that many rivals simply aren’t.
Pros: excellent haptics, great always-on screen, ECG, great health tracking, great activity tracking, 50m water resistance, solid battery, comfortable, quick-swap straps, Apple Pay.
Cons: expensive, only works with an iPhone, sleep tracking not great, blood oxygen data not that useful.