Flight does suck. I mean, really, everyone knows it. If so many people are dissatisfied with it, it's probably unbalanced. I have flight on a couple of my guys, totally for character concept. And I often am embarrassed on teams when I can't keep up with my teammates. I feell like "The Gimp" on a regular basis. It IS too slow.
But that's not my main concern, actually. My main concern is the accuracy penalty. I see no reason why fly should have this. I mean, Air Superiority is a flight pool power. It even has a special flying animation (which looks quite cool). But I can't hit jack with it if I'm flying? Come on! The -ACC is unneeded, it pushes Fly over the edge of crappiness, and it also eliminates Fly from combat use, which is just a shame. Flying attacks are way too cool to leave out of this game.