Actual results may vary; also see Google releases Android O to developers, promising better battery life and notifications (The Verge)
"In addition to battery life, Android O is expected to have simplified app notification settings and the ability to allow picture-in-picture display, so users can do things like respond to texts while watching videos in YouTube without having to close the video window.The next version of Android is supposed to have better battery life - Recode
Something that’s not changing: As with previous updates to Android, no one knows what fraction of Android users will get the update. Android might be the most common mobile phone operating system, but pushing out updates to users is often up to carriers and manufacturers, not Google.
According to Android’s developer site, a mere 3 percent of Android users have Nougat, which is the latest version now available. By contrast, 79 percent of iOS users are currently on the latest version of iPhone software, iOS 10."