@moose Honestly haven't noticed, as I'm rarely away from power for more than 8 hours or so. I use it maybe 2-3 hours per day, and have never seen it below 70%. In the same ballpark as the full-size iPad, I'd guess.
@moose I'd characterize the screen as "good enough"; the form factor makes up for the lack of Retina IMO. Here's a comparison I just took - the mini is clearly worse, but I wouldn't call it "terrible". http://flic.kr/p/dumVRZ