This review of DDAL07-12 contains some Spoilers.
I have DM'ed this adventure, and both me and my table enjoyed it very much !
First of all, I don't see why so many people complain about the lack of numbering on the map. There's not that many rooms to begin with, and the depictions on the map correspond pretty clearly with the text description. Maybe it would have been a different story if I would have had to read the adventure on the spot while DMing it, but I always prepare my sessions in advance.
Also, yes, some races (Yuan-Ti, Grung), spells (Heroes' Feast) and magic items give resistance/immunity to poison, which is the damage type of many traps in the adventure... but not all of them. Some are acid, and some are psychic. And of course, the encounters gave additional damage sources (fire, necrotic, etc.). If the party is lucky enough to have a character with the right race/item/spell, then good for them (as goes for other damage-themed adventures), but it's not a problem in itself. I did have a Yuan-Ti player in my group, but the non-poison-immune players still got their fair share of poison during the game. And besides, surviving a trap without issue can be quite rewarding & fun too, if roleplayed well by the DM and/or the player (for example, when my Yuan-Ti player went into the Giant Snake's Poison Dust, I told him that the air was "smelling like flowers").
I quite enjoyed the skull room, especially the fact that it accounted for players with means of flying (which all of my players had). The Medecine checks were indeed difficult, but I did allow a reduction on the check when one of my players cleverly mentioned that now that they understood that they were looking for specific races, they would be looking for an unusually small skull (halfling) and an unusually long-and-thin one (elf). I encourage other DMs to lower the check if the player is looking for specific race features of the listed races when investigating the skulls.
The fire snakes encounter was surprisingly punishing (almost putting the paladin to sleep), but the players won with clever tactics (for example, the Yuan-Ti doused himself in water from his Alchemy Jug, which I rewarded him by preventing him from catching fire). I was almost tempted to add additional fire snakes (as I know that Adventurers league's Encounter Difficulty does not account for magic items), but I prefered to save time on other parts of the adventure. After all, DnD is not only about combat, eh !
My favourite part of the adventure (and my players' favourite part as well) was the Nightmare corridor. They did have some talismans on them, but I thought that giving them all the possibility of fighting against their personally tailored nightmares would be an excellent idea, and I wasn't wrong ! One of my players, for instance, had the best moment of roleplay in his entire career when he fought against his nightmares, revealing his true face behind the mask he hadn't taken off since character creation, and telling his hardcore backstory to the nightmares. I'm always a fan of adventures that focus on character development, and this one did not disappoint.
I added some fire snakes to the final encounter, as I agree with other reviewers that it wasn't a particularly dangerous one, but the players had fun, which is what matters to me.
Overall, a pretty nice adventure. Yes, it has some problems, but they can easily be overcome.
[4 of 5 Stars!]