I haven't really had the time to read through the adventure, but just from the conversion notes provided by Keith it doesn't really ring true. I don't like the idea of the Ebon Triad at all, I would prefer something to tie in the Emerald Claw and Erandis.
Has anyone else edited or replaces 3FoE? If so with what?
I followed the conversion notes rather closely... the Hextorians became Emerald Claw converts who followed a strange interpretation of the Blood of Vol; the Faceless One became a changeling wizard who followed the Shadow; and the Erythnul group became a bunch of Dragon Below cultists, mostly dolgrim led by a dolgaunt cleric.
If you do that, I would include a stockpile of byeshk weaponry (or just one, to keep the loot balance) among the Emerald Claw's gear so they might have an idea as to what they're facing. That byeshk reduction on dolgrim can be reaaaaaally annoying for a low-level party.
Otherwise my party didn't have a big problem with the area at all. One of the players was near-giddy at the prospect of going through a labyrinth. I know a lot of people complain about the module, but I rather enjoy it; especially the fact that it can go from manageable to VERY bad with one wrong decision.
Check out this thread for some of my thoughts on the subject.