I'm not sure if this was the intent or whatever, but the map's pretty wide open. As it stands, a good sniper can pretty much dominate, while pyros and heavies are mostly useless. Every game I've played it's been a contest of snipers, soldiers, and scouts, with the occasional spy thrown in to mix things up.
Although given, the biggest games I've played there have been 3 vs 3's, so maybe things would liven up a bit with more people.