These are some ways Sentinel compares with two other major tracking services.

FEATURETimex Ironman OneSPOT Gen3myathletelive.com
Cost$$$$$$$$$
Secure tracking
Multi - purpose
Hardware Features
Waterproof casing
Long distance tracking
User accessible battery
2G
3G
S.O.S.
Usable near other GPS devices
User replaceable SIM
Auto-start for pre-set time
Size80 x 50 x 20mm (max)50 x 50 x 16mm87 x 65 x 25 mm70 x 50 x 30 mm
Weight99g (max)71g114g62g
Software Features
Set to your own language
User programmable update interval
User programmable data store interval
Course overlay for major events
Telemetry uplink from sensors (heart rate, steps/cadence, power, etc)
Bluetooth programmable from smartphone
Track & compare multiple users
Data Capture
GPS
A-GPS
GLONASS
Galileo
BeiDou