Excellent combination of asymmetric diplomacy, warfare, and strategic cardplay. The one drawback is that you really need 6 players, and they all need to have a clue, which means sitting down with the rules for at least an hour. It's tough to get eurogamers to do that. All that said, if you give me six players, and a free day, this is what we're doing.
RR Tycoon was already my favorite game, and I bought the Rails of Mexico map to basically make it equivalent to RotW. But I'm going to rate RotW higher anyway, because the Mexico map makes it much more fun for 2-3 players without needing to buy an extra map. Kudos for the extra addition.
RRT Comment: The game that got me into boardgaming. I love the feeling of building massive rail networks on the huge board, making tough decisions of taking shares vs. growing organically, and the uncertainty in when the game ends. Only downside is that although she loves the game, my wife doesn't like uber-competitive play, so she refuses to play with 6, and dislikes 5 somewhat, whereas 5 is the sweet spot for me.