Restart or Reboot Button
It seems small, but stock Android doesn't have a "reboot or restart" button when you long-press power. Only an option to turn off the device. Most other Android's from Samsung or LG have a restart, and now stock Android has it with Android 7.1 Nougat. It's a small change, but many users with a Nexus will enjoy it.
This is now built into stock Android, so in the future, all Android smartphones and tablets should have it. This is a good way to quickly reboot for improved performance or to fix small problems.