I would definitely recommend the Da Vinci Code room to a veteran escape-room junkie, but perhaps not for someone new to the genre.
The environment and props were high quality. The difficulty of the puzzles was very high - 9/10. The rigor involved in the puzzles may have negatively affected how much "fun" we had in this room. The theme, though well detailed, was not really linked to the room's title name - if you're going because you're a major Da Vinci fan, that's not really what the room is about. 3-4 people feels like the right number for this room.