Al-Qadim became a fully formed campaign setting with the release of the Land of Fate box set in 1992 (shortly after Arabian Adventures appeared). It is uneven at best.

The main problem is that Zakhara, the Land of Fate, is huuuuuuge and the detail given here ranges from sparse to uninspired. Most features of the region, interesting or not, are given only a few paragraphs of description. Much of the good stuff is, like Arabian Adventures, cultural, but it is also of dubious use for running a game – the details on the coffee ceremony are an excellent example of something that is of great interest but limited utility.

I suspect the reason for this that Zakhara is simultaneously part of the Forgotten Realms (this probably annoyed Ed Greenwood, the creator of the Realms, who disliked using versions of real-world cultures in his world) and isolated from it (partly to justify its unusual customs, partly to make it easily usable as a bolt-on for homebrew campaign worlds). I think including it in the Realms hampers the setting from really coming into its own because of the need for a kind of Realms orthodoxy, while keeping it isolated from the greater Realms also meant the setting was unable to directly benefit from its richness. It’s the worst of both worlds, really.

That said, the box contains some of my favorite Karl Waller art, which does more to infuse the setting with intrigue and adventure than all the text combined.