Ran it for a group in 1988... set it in Greyhawk, during a 24-month campaign that had seen us play the Slave Lords series, Ghost Tower and a few other modules... I think we ended up in Tsojcanth, but never finished it.
Could never understand why All That Glitters wasn't presented as a Greyhawk adventure... the jungle, the passage through the mountains to the sea of dust, the lost civilisation, etc... it was so obviously Greyhawk that it just wouldn't fit anywhere else.
Ran it basically as is (except for setting it in Greyhawk), but added a Sea Princes settlement on the jungle coast, called Port Elizar, and made it have a "Spanish settlers ripping off the local natives" kinda feel... and I hadn't even heard of Maztica yet. I remember a great fight in the sleazy tavern there... tropical night, lotsa drinks and a Sea Princes bully having his way with a native serving girl... seem to remember lotsa table-overturning and beer mugs smashed over heads kinda fun.
All in all, went down very well... seem to remember a particularly fun battle on a cliffside above the jungles. I think I changed the ending so that the treasure hinted to in the title wasn't just a Decanter of Endless Water, but was a whole underground lake, guarded by ancient Suel undead... rest is unclear (it was 17 years ago!)
All in all, my fave TSR adventure after Saltmarsh... which is still unbeatable in my books... since I've run it, or versions of it, several times.