I played Montsegur 1244 last night with my regular crew and it went well. The game's procedures are so luminously clear that I have a hard time seeing how any session could go off the rails. We did have some hiccups, though - more on those in a minute. First, a My Guy moment:
I played the mercenary archer Garnier, and it turned out he was a really nasty piece of work. He'd gotten Phillipa pregnant and then cruelly repudiated her, seduced and deflowered her sister Esclamonde, and agitated against the leadership of Pierre Roger at every turn. He promised to help Esclamonde escape the fortress, then cut her loose when the chance to steal part of the Cathar treasure arose. So, you know, total dick. Late in the game he had a road to Damascus-style conversion, hearing the voice of God and converting whole-heartedly to the Cathar faith - just in time to be murdered by the vengeful, cuckolded Pierre Roger. Total Montsegur win.
Perhaps the most interesting character choice was made by my friend Robo, who played Faye as his main. His Faye was a little girl who filtered everything through a weird, childish lens - being an orphan, she didn't really understand kinship, and decided her aunt and Pierre Roger were married "because they are often husband and wife in the woods." Naturally she asked Phillipa to explain this to her - can a man have two wives? Later, and more seriously, she distorted Cathar doctrine about earth being a hell and children being demons by persuading her brother to help her invoke the name of Satan (ruler of the world) to help lift the siege. This was not well received by the Perfects or, later, the Inquisition.
Of the survivors, only Esclamonde recanted her heresy - it was a pretty tight group of believers, and nine of the twelve burned.
Our only difficulty ws in early scene framing. The game started a bit slow, with long, ill-defined scenes. What I need to do in the future is provide a lot more backstory, and to go through the "how to make a good scene" information on the little play mats. I think this will help a lot and encourage you to do this, and maybe read the Montsegur, Faith, Consolamentum, and other info card in advance of play instead of at the stated intervals. My friends said they felt a little at sea, knowing nothing of the situation, and I played the game exactly as written.
The very best scenes were the ones most strongly framed - when Ian pimped me into accepting that Garnier was the father of Phillipa's child, that was awesome.
One final note - this is the third time I've played Montsegur and it is endlessly diverse in play. Understanding the relationships is helpful, but every person brings such a unique spin to the characters, and the mains are always a different combination. It has a high replay value despite the maniacal focus.