The Polar FT7M gives you the important functions you're looking for, like heart rate zones and calories burned, without making the usability overcomplicated. Plus, whether you're looking to lose weight or get faster, the unique EnergyPointer function tells you if the main effect of your training is fat burning or fitness improvement.
Strengths: Able to use it on the bike as well as for running.
Weaknesses: Can't hear the alarm
Reliability issues with the strap/transmitter/receiver.
I wanted a heart rate monitor in the form of a watch so I could use it not only for cycling but for running. This one fit the bill.
The alarm is barely audible.
After the first 5 months or so I started to get zero heart rate readings and the error message "Check heart rate monitor strap." The reliability of the HRM has declined since then. It will barely register any heart rate now. I've tried adjusting the strap, using spit to wet it, conductive gel helps but does not completely cure it. I've gotten in touch with Polar about having some warranty work done on the unit.