With Android 7.0 Nougat users enjoyed much better battery life. Google worked hard to refine the experience, has something called Project Svelte to make devices smoother and more efficient, but also an improved version of "Doze". Putting apps into a deep-sleep state for better battery life.
However, Android 7.0 Nougat wasn't all great for some. Many Nexus 5X owners complained about battery life issues, unusual drain and other things. This update will also be great for Nexus 6 users, who got N back in October but had a similar problem.
With Android N Doze is faster and more aggressive, and puts apps into a low-power state once the screen has been turned off for a certain amount of time. It will be more aggressive the longer the screen is off, too. Saving more and more juice. Eventually shutting off many background processes, but still letting important calls, texts, or emails come through. A similar process takes place on iOS devices, and Google's doing everything they can to make Android last longer than ever before.
If you want better battery life on a Nexus device, Android 7.1.1 should deliver that. We're hearing a lot of reports that Android 7.1.1 brings many devices close to Google Pixel performance, which is one of the best Android smartphones ever made. So yes, get Android 7.1.1 Nougat today.