But yes, I like overland flight that much.

I don't even care if a character has to hyper-specialize to get it. In fact, I would actually consider that better. It would make flight much more rare and special. Maybe you have to be an air elemental savant to get persistent flight, or you need a feat chain to improve the flight spell to make it persistent. If such options exist, I'm good to go. Otherwise...not so much. I don't play fantasy games to be constrained by the same rules as conventional reality. I play fantasy games to take a vacation from reality. Otherwise, what's the point? I may as well play monopoly.
And overland flight is just one example. What about water breathing, or shape-shifting? Abilities that allow characters to explore their environment or form in ways that we can't are what fantasy is all about. Sure, combat can be fun, but I'd much rather role-play the weather mage who loves flying through storms, or the druid who loves turning into a shark in order to explore the ocean depths. If 4th edition can't simulate those character concepts, I'm not interested.