Count yourself lucky.Nope!
It's one of the worst adventures in D&D history, not because it's a terrible adventure - it's a somewhat mediocre one, or perhaps even a good one with a crap ending to rival Battlestar Galactica or pre-patch Mass Effect 3 - but because of the lasting vandalism it did to Sigil and Planescape.
Monte Cook had written a number of Planescape adventures previously, ranging from "good" to "amazing". So people had high hope for him. Faction War destroyed literally everything good or interesting about Planescape (except the Blood War, but I forget if that predates Planescape). Swept it away. All the in name of drama. Basically took a giant crap on the setting from a very great height. Imagine if someone took Dragonlance and just killed off all the dragons, and said they were permanently dead and never coming back, oh and also the Knights of Solamnia and the Wizards of High Sorcery all died or quit their jobs. And so did the bad guys. Except it's worse than that. Or like Eberron, and suddenly Dragonmarks all stop working, and everyone with a Dragonmark gets murdered, and there's no mystery, everyone knows why it happened, but Dragonmarks are over, and also the magical technology? That stopped working too.
That's basically what happened in Faction War, because Cook has (almost) all the Factions either wiped out entirely, or driven out of Sigil, never to return.
As I've noted before, Cook swears blind that he didn't mean the situation to end this way, that most of the Factions would have been restored in the next adventure (which never happened), but frankly, I'm skeptical, because he killed off some Factions outright, disbanded others, exiled the rest, and many of the most interesting ones were wiped out or disbanded.
Basically it was massive vandalism. Monte Cook had absolutely nothing to do with conceptualizing Planescape (that was all Zeb Cook), and it seems to me like he wanted to do "Monte Cook's Planescape", just like he did Monte Cook's this and that later (like his hilariously bad take on World of Darkness, which is near-legendary, and not in a good way - I love his Arcana Unearthed though). Anyway, it was a crime, and should be put right. Ignoring crummy canon from the past would allow it to be put right.
Anyway, when people say how much they like Planescape, they're referring to pre-Faction War Planescape. The vast majority of D&D fans, even deep lore ones like you often have here, don't know much about Faction War or even that it happened in many cases, let alone that 4E (psychotically) canonized it (I think 3E did too, to be fair, but 4E really dragged Sigil through the mud lol - and in such an otherwise-good book as the DMG2!).