Does anyone use a Nike heart rate monitor? How do they perform? How are they compared to Polar? I was looking to buy a HRM this weekend, and was about to settle on a Polar, and then saw the Nike ones at WatchStation store. I bike into work now and would like to train for an hour or so before going in and thought a HRM would help me train better. Like I said, I was going to get a Polar, but Nike's looks more like a real watch that I can wear when not training.