Ars Magica is one of my favourite fantasy roleplaying games, second or third only to DragonQuest and Atlantis: The Second Age (in its various incarnations). While I ran a good three years worth of Ars Magica, the players in both groups never really got into the game because of the troupe play issues. They always felt that it was hard enough playing one character, let alone three or so! Though they did get what the game was all about. They did play the game, as they enjoyed the game world and the mechanics of the system at the time (with a truly neat and creative magic system), but they just didn't want to play it any more after that.
While I'm running the Atlantis: The Second Age RPG these days for my fantasy fix, the new game that will be out in the first quarter of the new year, Sorcerers of Ur-Turuk is also a troupe play game, uses the WEG d6 system, and is sword & sorcery in Persia! That could get my players back into the troupe style of play. We'll see.
But I still do miss the late 1980s and early 1990s games I ran of Ars Magica. So thanks, knightbane, for bringing back the memories. :)