Basis Carbon Steel Edition

Automatically starts tracking ; Accurate heart, sleep monitors ; Tons of biosensor data

A bit bulky ; Limited activity types ; Short battery life

Bigger and brainier than your average activity tracker, the Basis can track everything from your heart rate to how well you're sleeping.

In-depth sleep tracking ; Slicker than its predecessor ; Habits feature helps you push yourself

Bulky ; Pricy

Like its predecessor, the Basis Carbon Steel tracks just about everything, but even with a slimmer design, this fitness watch hardly qualifies as sleek.'

Auto-detects running, walking, bicycling, and sleeping. Measures REM, light, and deep sleep automatically. Sophisticated and comprehensive measurements. Zeroes in on habits rather than raw numbers. Excellent Web interface. Wirelessly syncs over Bluetooth.

Doesn't measure distance. Screen is dim.

During the short setup for Basis, you install a small piece of software on your computer that uploads data from the watch to your Web account, where you can see your fitness habits over time. You can also sync data via Bluetooth to the mobile app for...