I have a Series 0 AW that I may keep to use at night for sleep monitoring once I get my S2. Don't really need to sell it and used prices aren't that great anyway. Please excuse the first world dilemma. Idea would be to charge the S2 overnight on my nightstand, and wear the S0 overnight (and charge it during the day). Will the fitness data appear seamlessly on both watches (and also in Activity app)? Same with the sleep data? Plan is to use the "Sleep Watch" app. TIA.