I like my diagonal corridors curvy, not with strange nooks that make you impossible to flank by creatures that are diametrically opposite to each other around you.
We solved all of the hex problems decades ago for any shape or size area.
WotC introduced the concept of "almost all dungeons have right angles to them and north/south east/west dimenions completely divisible by 5 feet" and a large chunk of the D&D gaming community bought it hook, line, and sinker for the most part.
Squares in 4E still have buggy problems. For example, if a medium sized creature is flanked diagonally, he can shift 5 feet and be 5 feet away from the foes, allowing him to range atack either of them.
If he is flanked north/south or east/west and shifts 5 feet away from the foes, then he cannot use a ranged attack without provoking an opportunity attack from one foe or the other or both.
Hexes are vastly superior, you just have to get people past the small learning curve on how to use them correctly (regardless of shape or size of the room). Once you do that, Fireballs appear to be spherical again and diagonal movement across a room is back to being more movement than north/south, or east/west, and would assist with the Defender concept of defending easier.
WotC would be smart to have optional hex rules. There are some players out there still bothered by the movement and area rules of 4E that might play the game with hexes. That might not be you, but I've played with a lot of people with hexes over the years in a wide variety of games where it quickly becomes second nature.
