Im in the same situation my Gear sport has completly drained through the night for the last 3 days, I have tried a reset today but checking my gear its drained %65 in the last 5 hours? not happy at all :(
All - here is the response that i just received via US Customer Service via twitter:
To increase the battery life on the Gear after the update please follow the steps below ↓ •On the Gear tap on setting; •Tap on Gear info. •Tap Report diagnostic and usage info (Disable this feature) Test the watch for a few days to see how the battery works.