Fortnite released yesterday so I did use my phone a bit heavily today, managed from 6am to 11pm without charging.
My workload consisted of Fortnite(30 minutes of play time I'd have to guess), Instagram, Snapchat, Slack, Messages, Camera(some shots), few phone calls(on and off speaker), Safari(Lots of browsing, I'm a heavy safari user during my day), Adguard toggling, quite a bit of notifications which showed up as some battery usage(guess its good I have a black wallpaper on this OLED screen), ParcelTrack, eBay, Some Reddit, Music App, and finally the Mail app. This usually isn't what my day consists of, but the X handled it great.
8 hours and 25 minutes of usage
16 hours and 17 minutes of stand by
Ending at a beautiful 12 percent, very impressive battery life. I usually end a normal day with 60-70%(6am to 3-4pm)