I have both a shoe one for a pair of my running shoes that I keep at work, and a wrist one for both riding and running (the shoes at home don't have one on them). I've done 20 mile runs with the wrist ID on and haven't even noticed it (other things start hurting/bothering me more on long runs than what's on my wrist, like my leg muscles!!). Plus, I switch bikes depending on if I'm commuting or not, and each bike has a different pair of shoes, so the wrist is more versatile for me than a shoe one would be. Sometimes I forget I'm wearing it and wear it into the shower.