I got the update early yesterday morning, and I haven't had the DQA error at all; some people were saying it was because of a certain app installed on the phone, but if that's true, I guess it means I don't have the said app.
I know a lot of us got the update shortly after getting the phone, so it may not be easy to compare the battery life before and after the update, but what would you guys say? Did your battery life get better or worse after this update? As for me, I don't think it made a difference on my S8+.