Jim did some amazing work that allows the terrain brush conversion along the other support necessary to do the texture blending etc. The size capabilities are quite vast. The old restraints in the editor were +/- 4096, the new restraints are +/- 131072. Now there would be some pretty substantial floating point precision errors seeing that distance but the fact is you can make HUGE maps. As long as you have valleys and canyons or buildings etc. you can do some truly amazing things. John pointed out that people will possible run into surface count limitations and so on but this should not be much of an issue. As far as FPS issues go, the map with the large gothic looking castles runs about as fast as many of TA's indoor maps...