honnestly its not as bad as people say. on room 1 and 2 i used one i game hint each, but both were my fault. the first the clue was on the damned object and i could not see it. the second i passed many times near the correct place to use my object but didn't see it. both were avoidable.
on the 3rd room, the infamous bank level, there was one puzzle i could not figure out, the stamps. even with the in game hint it was obscure for me and i pulled out a soluce. the specific puzzle was weird i agree. on the rest of the bank level not problem at all not even an in game hint.
last room no problem, no hint needed.
so can we rate the dlc badly for 1 poor puzzle on all of the room ? no. its fine.