I'm sure you've popped into the "Battery life for 13 and 15..." thread. I know it's 4X pages now, but there is a lot of good info. Lot's of documented fixes or workarounds. Key is understanding what the CPU and rest of the computer is doing. After you understand, you can just run whatever you need and have reasonable expectations for battery life. I also get 8-9 on light usage and can get more if I tried. The tb's battery is smaller yes, but the CPU is also more efficient. You just need to be aware of what makes it kick in. If you're CPU is going nuts for no reason or seemingly innocent apps like Safari are running high watts, reinstalls of Sierra seem to reset everything, without reinstalling anything, painless 5-10 minute process. To get 8-10 hours on the tb13, you need to be running at 5-7 watts on average. If you're running more, something needs to be fixed. Anyway, check it out. The battery claims are REAL. You can get it without any massive change in your workflow. Normal disclaimer, Apple definitely should have optimized this software so that your battery life is good out of the box. But you can make it work before Apple updates Sierra in the future.