Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.
iPad Air 2 here:

iOS 15.1 much worse battery life compared to iOS 14.8!

Tip: Update to 14.8.1 — wirelessly— do not upgrade via iTunes, where you only have the option of jumping to 15.1 and aren't given the 14.8 to 14.8.1 option!

I found that out the hard way! Thanks, Apple, a whole bunch! /s
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.