I'll have to agree with Chuckster here: I don't find learning new map layouts to be much of a problem at all anymore, simply because of the new minimap. If there's a proper, 2.x minimap included with the map, getting used to it is a matter of only a few games. Even hydrosity, with its huge size and complicated tunnel network, took only a couple of games to get used to. I would still find the occasional vent I had until then overlooked, but overall, I knew the map quite well. If you find that getting used to new maps takes too long, I'd advise using the minimap more.