Been doing some reading and apparently at least among aficionados of devices monitoring heart beat rates the wrist is considered pretty poor compared to say a chest strap. I have been watching my heart rate because ironically I have recently had problems with a racing heart (I hope just due to stress at work). Curious if anyone has read a comparo or knows of one on the ability of the Watch to get an accurate reading, and what the limits are. My impression is: it's fairly accurate for most people for resting rates and light activity, less so the more intense and irregular the activity is. Thoughts?