I think I'd prefer a map where all tiles were slightly irregular, to avoid having 12 special tiles. Something like this: http://i.imgur.com/jQwYqZB.png You can make it by putting a bunch of point electrical charges on a sphere, letting them repulse each other, then taking a Voronoi diagram of the result.
(Author here) I had been trying to avoid the irregularities for that particular project because the storage of extremely large game maps saves a lot of space if you can use a regular grid instead of an irregular graph. (Certain algorithms like grid distance also run much faster.) If you embrace irregularity you can get some pretty neat maps, like this one from Andy Gainey: http://experilous.com/1/blog/post/procedural-planet-generati...
