Buried Deep is one of the most immersive and impressive workshop maps I have played. It is crafted with an insane level of professionalism, atmosphere, sound design, and balance, more than other campaigns have done.

The first three chapters are near perfection. The latter two can fall off slightly in quality, but are still good chapters overall. The holdout sections are always fun and require you to use your head and resources to conquer, you can't mindlessly go about this campaign and expect an easy time.

Having those moments with a coordinated team, watching each others backs, playing through this map and beating chapters with strategies you crafted together, it's pristine L4D2, it's exactly what you could want out of a cooperative game like this. The author is not kidding with his quote at the bottom of his addon description:

"WARNING! This campaign will test the skills you have with the game, it was made with gameplay experience in mind, and thus will heavily punish you for not controlling the hordes or not doing actual Team Work."

Players who did not read or heed this warning are the ones who say the map is too hard or unfair. In reality, while it does pressure you, you have more than enough supplies to hold out. The only area that I would consider slightly imbalanced is the Chapter 4 holdout at the doors, but even then their are ways to handle it easily. I'm just impressed by this campaigns ability to be difficult, but fair, you will not be put into situations you simply cannot win, you just have to be smart with your items, supplies, and teamwork.

In conclusion, I genuinely think Buried Deep is the best custom campaign on the workshop to the right kind of player. This map is their holy grail.