Fitness Trackers

What you pay upfront for the hardware versus what's locked behind a recurring membership fee, and whether the free tier is actually useful on its own.

How many days you can realistically go between charges, and how disruptive charging is to continuous tracking (especially overnight sleep data).

How trustworthy the heart rate, sleep staging, and workout/GPS data actually is, based on the sensors and validation the brand has published or is known for.

Whether it's a screenless band, a ring, or a full smartwatch — and how much you get beyond fitness tracking, like notifications, apps, or payments.

Whether the device works fully regardless of your phone, or whether picking it commits you to one phone ecosystem.