I actually think the reason that it does so well, is because the best strategy is fairly obvious. It's easy to see what you should do. You get dealt a hand of tickets and you want to connect them as efficient as possible. Almost everyone will pick that "strategy" up right away and I think that's part of what makes the game so easy to get into.
This is my wife's favorite game, therefore I have gotten in a lot of plays, with the Mystery Train and without.
I am not as experienced a gamer as most of you, but I'm not convinced the best strategy is fairly obvious. I have seen employed numerous strategies, each with varying results. Get a long, cross-country ticket or two? I've seen it win and lose. Concentrate on routes of 5 and 6 cars and try to end the game early? I've seen it win and lose. Connect a bunch of destination tickets? I've seen it win and lose. Try to keep others from connecting their tickets? I've seen it win and lose.
(Let me interject an aside here. I played one game against my wife. I completed no destination tickets and lost about 20 points. I didn't have the longest train. I only had a couple of routes of 5 or 6. And I didn't initiate the end game. I won. I thwarted every single thing she tried and beat her by about 15. I reduced her to tears. I'm not happy about that. I was just playing to win. Despite that, it's still her favorite game, and we're still happily married.)
Understanding the game play is easy, but after the first few turns, every turn represents having to make a delicious choice. Do I claim that route or do I draft those cards? If I don't claim that route, will it still be there next time? There are different paths to victory. There are constant choices to make. Game play is quick; it moves along well. It scales well. It works well, and yet is a little different with 2, 3, 4, and 5 players. I think it is brilliant design work by Mr. Moon and wonderful execution by Days of Wonder.
It's not everyone's cup of tea, but I don't think any aspect of the game is flawed, including the jokers. I think they keep the game moving, making it easier to claim certain routes at key times. I think they give a player a little more control over how to play his hand. Otherwise he's forced to sit there and keep drawing, hoping to get that fifth red card he needs. With the jokers, it's far likelier that he can nail that last card and then claim the route. And the mechanism for reshuffling the draw pile when 3 jokers appears is solid and unobtrusive.
Needless to say, I'm a fan of the game. I respect how well it all works. I also thoroughly enjoy playing the game.
Steve, who has been snowed under with other work and very quiet lately
Seth, I was making the distinction because Jeff started talking about "you guys" while I think I have quite a different opinion on this matter than you have!
No worries, eh?