Really enjoyed this. A "superheros are people too, with all our petty human disagreements!!" book without, hrm, the excess of some in the genre. Really liked Karen, found her very believable and interesting.
Saw one of the plot twists coming a MILE away when the Nerd Boy got away with a GIANT BABY NICE GUY (TM) fit when she started dating someone else but I didn't see the other!
The opening's a little rough, esp with the incredibly dubious sex that happens within a first couple pages, but it really picks up.