While mine's not doing THAT bad, it's clearly worse than it was with 8. I could normally go a full day without sweating it at all, with light to medium usage: I make a few calls in the morning, listen to some tunes on the way in to work, maybe send a few texts, and then the ride home has a few more calls and a few more tunes. By the time I would plug it in, I'd be down to about 40% or maybe, on a bad day, 30%.
Today, same usage, I'm down to 55% right now (at 3:40pm). I've turned off as many bg processes as I could find, including Cortana's background processes (I have a feeling she's the culprit, but I'm not sure. Oh wait, I can check.
Hm. Insider says that my usage went down DRAMATICALLY after I turned 'her' off. Until then, every reporting period was -5% or -6%. Right now, I'm at -1%. The reporting period appears to be 20 minutes.
I wouldn't take this as the final answer, but it sure seems... suspicious.
Anyone else turn off the BG Cortana stuff to test?
I really hope MS is going to patch this. I don't want to have to worry about always looking for a place to charge.