I finished up a playthrough of Shackled City, using 3.5 rules, not too long ago. We did skip Chapter 12, Asylum, at the very end though. With Adrimarchus being locked up, my players didn't see the need to go fight him and I had been treating him as this nebulous force that was driving the antagonists of the campaign.
The campaign flows pretty well, though there are a few sticky points. Chapter 6, Test of the Smoking Eye, is one and anyone with any sort of genre saviness is going to be onto the big reveal long before it happens.
Shackled City is officially set in Greyhawk but there's nothing really tying it to that world. In fact, I think Cauldron is off the far southern edge of the official Greyhawk maps. So if you want to port it to Forgotten Realms you won't have a problem.
The biggest pieces of advice I can give you if you run Shackled City are to first start foreshadowing as soon as you can. The paizo forums, theRPGenius and pretty much anything written by Delve's Deep is a gold mine. If you don't find ways to start hinting at the Cagewrights early on they become a group of mostly faceless villains. Second, there is a some NPC bloat. Find out who and what you can cut for your group and who you can reuse.
I have been slowly writing a document on all my thoughts and changes for the campaign. If you decide on Shackled City, I can share it with you. Who knows, it may give me the drive to hurry up and finish writing it!
