I bought the AW specifically for medical reasons. More precisely, I am a Type 1 diabetic and wear a Continuous Glucose Sensor by Dexcom. I have the Dexcom app on my AW and it has been an extremely useful and will only get better. Not to get too technical but the current setup requires the Dexcom receiver with bluetooth which talks to my iPhone/AW. In the next generation (G5) the transmitter (which is attached to my body) will have bluetooth built in and will be able to talk directly with the iPhone/AW. Eliminating the receiver requirement will be tremendous.
Currently, my AW allows me to not have to always have the receiver on my body everywhere to see my blood sugar. I can glance at my watch in the pool/at the beach with my kids (yes I wear my AW in the pool) instead of having to get out and look at the receiver. I can just leave the receiver in a backpack on the bench while coaching my kids baseball teams. Being able to just stick the receiver in a shorts pocket/backpack and not have to fumble with it to see my readings is extremely convenient, not to mention significantly reduces the likelihood of losing it or dropping it. Plus, the other night my son came over to me while I was taking a nap on the couch and looked at my AW and woke me up and said "dad your watch says your blood sugar is 63, do you need some juice?"
Pretty cool and very important to me to say the least.