This is the best expansion that's ever been made.
The new story and lore additions are amazing.
3 of the 5 bosses are all time greats easily.
The level design is extremely tight with plenty of secrets and new horrific locations to find.
It has some of the coolest weapons in the game.
The music is incredible.
The complete package. A perfect DLC. The game was already a masterpiece but this elevates it to a whole new level. Please play it.