I read this on the BGG forum and I think it's interesting:
One final point, even though almost everyone uses a map nowdays instead of the region cards there are a couple small yet important difference between the two methods of play. When the region cards are used this forces the resource player to choose his site path before moving. This can be important when there are 2 or more valid paths between the starting and destination site. Second, the hazard player is able to see how many regions the resource player is moving through before the movement/hazard phase. This can better enable him to gauge what hazards he will be able to play (e.g. you know you won't be able to play a were-worm if you only see two regions face-down because the were-worm requires 3 wildernesses). Both of these differences only show up when the resource player is moving more than one company because then the hazard player is better able to judge when to hold on to a card to use against the 2nd moving company, or to play it against the first or discard it. The effect of using a map instead of the region cards is to make things slightly safer for the resource company when using region movement.
For reference, the tournament rules state that:
Movement
Maps of the regions of MeCCG may be used in place of region cards in Council of Elrond tournaments. If two or more companies move on the same turn, then each company does not have to determine the site path to its new site until the beginning of it's movement/hazard phase.
Wizard companies cannot use starter movement to or from sites in Gorgoroth. If using region movement to or from sites in Gorgoroth, they must move from a site in Imlad Morgul, through either Nurn or Udûn, or use a movement enhancer like Ash Mountains or Eagle-mounts. Such sites may be reached normally with Under-deeps movement.
The use of the map for movement (in the way everybody uses it today) hides information from the hazard player. I'm not sure about whether the tournament rules mean to change that aspect of the standar rules or not.
