Look, one of these tests is going to produce interesting results eventually…
I charged my iPad Pro up to 100%, turned the screen to 100% brightness, opened a Numbers document, and comitted to typing a little gibberish every minute for 2 hours to make sure the keyboard stayed active and screen stayed on (with the backlight on about half brightness).
Two hours later, the results were remarkably boring. The battery drained about 10% faster with the Magic Keyboard, which if we extrapolate out from my 2 hour test (I ain’t doing this all day…twice) we’d hit zero after 9.67 hours with the Magic Keyboard, and 10.7 hours with the Smart Folio. That’s certainly a difference, although it’s kind of within the margin of error since I was not able to totally isolate background network access and that sort of thing.
I’ve heard other people comment on degraded performance with the new keyboard, but I didn’t notice it anecdotally when I was using my iPad like normal, and my “controlled” test didn’t show a notable difference either, so I’m completely happy with the battery life on this thing.