Battery life has been great for me as well, I’m able to leave the my 8 off the charger and not worry about it being dead in the morning. The biggest thing I noticed was that apps that were abusing background no longer do that (notably ShopSavvy with hours of background usage while suspended and BAR completely off).
On another note, I also signed out of iCloud and signed in because of weird issues I was having after 13.6 initially. I had the famous “iMessages in iCloud are not synced” so I wanted to get to the bottom of it. After some tinkering with toggling it on/off and waiting for the sync to finish I think that may have helped also so make sure all your iCloud stuff is in order.