Pretty much any map theme will do, as long as the map
- has at least few good spots to place snipers (also the kind that can be reached in a reasonable amount of time, might want to consider making larger maps with more aliens, since battles tend to be really short)
- few extra tiles of free space around the aircraft, so that it doesn't block movement
- adequate amount of scattered cover spots (big rocks, barrels, trees, boxes, cars... )
What really bugs me with current maps (system) is that soldiers fire from their waist height, making line of sight and line of fire two different things. Could the line of fire be made to use the same line as the line of sight? It's really annoying when you can see an alien on a rooftop but the line of fire is blocked by the edge of the roof due to soldiers firing from their hip.