For what it's worth, mine gets about the same battery life when I watch YouTube. I guess I just don't watch YouTube that much to notice. I certainly don't have battery issues that I notice though. Before I rooted and went with a custom ROM, my battery life sucked to be honest. Now I can use it all day without worrying about charging it. I can easily go 16+ hours, whereas before I had to make sure and charge it ~8 hours. That's without every touching the Power Saver setting. However, it certainly depends on what you're doing with your phone because you can easily drain your battery in under 4 hours depending on what you're doing. There's good apps for battery savings that can be used - however your issue is something you're seeing right while using YouTube. All I can offer is that your results are the same as mine, while using the app. Other than that, my battery life lasts quite a long time with A/V, Weather apps, multiple email accounts, Live wallpaper, no power save, auto-brightness, etc. Don't know what others are experiencing but it's always possible that it's the app.