Redtooth Ridge is the only Advanced Adventure that comes directly from my campaign. Most of the time, the games I run are too customized to be turned into a suitable-for-all module, but this one managed to make the cut because I was starting out with a brand-new group, and 1st-level modules tend to be the easiest to translate from my table to the tables of all gamers.
That said, 1st-level modules also tend to be quite hard to write for public consumption as they’re generally very similar and you don’t want your modules looking like something that’s come before. Finding new ideas is also more difficult at low levels because of the power constraints. Redtooth Ridge was powered-down from my table into the final product because my players were all very experienced. For instance, the vrock (yes, vrock!) that appeared at my table doesn’t show up in the finished module. But the vrock did provide for one extremely memorable scene: My wife, playing a trusty dwarven fighter, who upon seeing what appeared to her as giant-chicken-footprints in the dust on the floor, decided that clucking like a chicken was the appropriate way to see what critter lay behind the prints. Needless to say, that infuriated the vrock and it immediately came to investigate. A few rounds later the cleric put it down and managed to save the rest of the unconscious party. Fun time!