Cosmetically, this XT1900-1 model phone is probably a 9/10.  I always kept a case on it and over the screen.  It does work, BUT the power button is broken.  There's a workaround:  use the accessibility menu, which means you can tap the person icon at the bottom of the menu to lock the screen, restart the phone, etc.  HOWEVER...if the phone runs out of battery, you're in a pickle.  You have to use the Android SDK tools on a computer, download the Motorola Device Manager, plug the phone into the computer's USB port while holding the volume down button, and use "fastboot reboot" from the computers command prompt to power on the phone.  Yeah.  It's complicated.  But the details are here: https://www.reddit.com/r/MotoX4/comments/bhjtkq/comment/em90alq/  

I bought it through Google to use with Google Fi; it's unlocked and is running Android 9.  Accubattery has the battery health at 86% or thereabouts. That might even improve as you start charging / discharging it again...this phone has been sitting for a while as a backup.  

Or maybe you just want it for parts, which is fine, too.