I was interested in this a while back. I started a thread on it and got a very cool response on WW. My wife got wind of it and gave me one as a gift. I have been wanting to update this thread with results from a decent ride, which has not happened since long before child #3 was born
Monitored: HR strap, speed/cadence
Sample rate: 2 sec (1, 2, and 3 sec options)
Screen: always on
Conditions: hot as hell
Speed: Granny passed me
Duration: 6hr, 8min
Battery left: 5%
With two devices monitored, the device can deliver a long ride with two or three second rates.
I have used it in the rain one time.
What I do not like:
-Closed format as Jmilliron stated
-It cannot be customized to be just a cycling computer. It is always equally a pedometer, calculator, golf coach, eliptical, every sport they could think of device. You can configure the workout symbol that you swipe toward to be a road cyclist (with a pointy walmart helmet). Whenever you turn it on, it is a watch first. There is a setting that I discovered called "auto-run", which may help with this.
-You can see by my avatar what I think of Google. Not only is this device powered by android, Motorola mobile is now owned by them. Who here on earth deserves to have a great crystal ball/omnipresence to peer into our lives? Corruption always follows great power. The less Google I have in my life, the better. But that is a subject for a different forum.