Only map I can think of that gives an advantage to UD is PI against Ne, but obviously its a real bitch for us against the other 2 races. TR I think is a terrible UD map, but I know plenty of people would disagree. Obviously LT is shit for UD too since its so expansion dependant. Basically, I'd say any map where its easy to fast expo (PI, LT, 2R) is gonna give you a hard time against Hu. Any map with a tavern will give you a hard time against Ne (TR in particularly) and any map in the game is probably gonna be tricky against Orc.