Garmin 920XT is a huge improvement over the Garmin 620
A few key features:
- Daily activity tracking
- Sleep tracking (with built in accelerometer)
- Smart watch features (see emails, text and other notifications)
- Indoor run tracking through accelerometer
- VO2 max estimates
- Race predictor based on last runs HR and pace
- Large easy to read screen
- Vertical Oscillation tracking (with HR monitor)
- Ground contact time tracking (with HRM)
Aaron Olson 