cos

I'd definitely pick invisibility. Flight has too many negatives -- I don't even like to drive, so I'm not sure why I'd want an extra dimension to worry about; it's too conspicuous; and if it turned out to be fun it would be lonely to be the only one. I'm actually not sure invisibility has that many positives, honestly; most of what it could get me I either already get anyway (being left alone in public) or I'm better off without (the ability to eavesdrop -- likely to lead to knowledge I'd wish I didn't have, and maybe the temptation to spy on e.g. politicians doing evil deeds). But I might find a use for it, and flying would be worse.