My opinion is that you forgot the biggest concern; "Google sued for data-mining students' email" is another post on HN today. The features presented (est. time

My opinion is that you forgot the biggest concern; "Google sued for data-mining students' email" is another post on HN today. The features presented (est. time to work based on my route, etc) is not data I want to be present in googles dataset. On the other hand these wearables are pretty great in this sense, for the first time you are the customer (usually the businesses buying ads are).