I have only played in a single game set in Al-Qadim and I have never ran any games in this setting. I didn't own a single Al-Qadim book until just a couple of years ago. But I remembered my play experience from 1994 quite fondly and I fell in love with this campaign world... so I started collecting it all. I'm still working on the collection, very slowly, as a casual hobby.
Anyhow. I've already said a lot about Al-Qadim in other posts. For this mini review I'm just going to link to all the posts I've made so far talking about Al-Qadim.
It's so damn good. Even though it has it's flaws... which are almost exclusively related to rushed production and recycling cover art and what-not. But on the whole...