First my stats P4 1.18 GHz, 512 Megs of ram, Geforce4 ti4200 128 Megs of vram. My PC can't run huge unit size very well, flaming missiles and/or full stack army lag fests were deal breakers. I know use large and it splits the difference between medium and huge. My cities have slower population growth than medium but not at the glacial pace of huge. The and AI and myself have never de-populated cities training armies, and the armies on large are big enough to have that climactic battle feel about them. I have had battles between full stack armies on medium. But that was usually between me and pontic amries of eastern meat shield,,err infantry. The AI has it's usual practice of not pulling together a full stack until their at the place where they are gonna attack.