It doesn't take as long as you may remember - I've got a bunch of apps that require me to run adb commands for them & if all else fails - a Factory Reset can do an amazing job of getting your device running at it's best 🐧
I'm thinking that since @ziom has "customize nuances in app" as I do (but I Factory Reset) that the Update Script in the OTA may not be designed to accommodate customized apps - Which MAY result in lag after applying the OTA.... but that's just a guess 🐧
I haven't noticed any lag after the first hour of rebuilding cache etc, but I DID notice my recent apps button stopped working, and I can no longer swipe up for app drawer, it's like the drawer starts to open but then gets stuck. Might have to try the backup and restore via Smart Switch PC
I'm assuming faster is associated with a refreshed operating system... and quicker drain is in part because the battery optimization is starting from scratch again, and as a user, you are likely to fiddle with your device more after an update...
well... I can at least say for sure the finger print sensor is faster. probably the animation is making me feel like everything is faster too. yeah I agree it'll normalize in a week. but let me enjoy my time with it lol