On closer examination, we do appear to have an large Ice Spike biome at the very edge of the map, half in and half out of the border. Expanding the border would thus net us the rest of that biome and a large mesa biome as well. However, no Mushroom island, which means no mycellium. I suppose we could live with that, and the central spawn area is pretty useful for our purposes, but I'm not really that impressed with the world in general and I'm leaning towards tossing this one out. Here is the map so that the rest of you can see it and share your opinions; the HD portion is still rendering at the time I posted this:
http://orgcraft.org:8123/