What is there to say? Play the base game until you get bored. Stop playing for multiple months. Start a modded server with your friends. Play that server for only 2 days before putting the game down for a year. Repeat.
The game ran poorly even with a good pc well above the specs recommendations and the story was not long enough to justify the extreme price as the other content in the game such as warzone is FREE
This game may be one of the last great FPS from it's time, to have such large community goals in the multiplayer that everyone worked towards to the story of zombies. This game was great even with the flaws.