Actually, if we were most correct about it, Wings of the Eagle should probably be a Transmutation, since you're changing yourself, not making wings and attaching them like you were Daedalus or something.
An additional thing on the perceived power, you should compare the spell to Master Air, the 2nd level Druid spell that gives flight for rounds/level. No self-respecting Druid bothers with Swift Fly when they have that.
Considering a Pally is only getting 1 or 2 spells at 4th, getting 1 round of flight (CL 1, remember?) isn't breaking the bank when the full casters are throwing around fire and holy smitings of their own.