Typically the only time I've used sprint in battle is every now and then for the second boss in wp when he targets me. And also to run past the stalker, and it is annoying using it to run away and then having to wait for all of my tp. I don't really know of anywhere where any of the classes would actually NEED to use sprint, its just something that can be helpful to every class, so yeah it shouldn't just penalize melee dps. I think a longer cooldown and no tp/mp drain would be very fair.