I would rate it easy to medium difficulty with ZCT mod enabled. I beat it on my first attempt co-op so it's nothing too difficult. There is plenty of open space to maneuver with decent weapon selections throughout the map as well as plenty of random box locations. There is some searching involved which may bother the more impatient.
It's a large map. Unfortunately you won't spend time in a lot of the areas. There are clearly better areas to hold and I found myself building points and opening up large portions of the map at one time. There are some teleporting devices but I didn't find a need to use them. I was never in a tough situation where it was needed.
I think it has a cohesive visual look to the map and the areas blend together to be an airport. There are some good sound effects as well to enhance the experience.
I think it's a pretty straight forward map besides the searching around for some triggers. So it moves along like most maps. I do wish there was some type of update after objectives were completed. For example if there are 5 Weapon Cache, then it would have been nice to be notified that you completed 1 of 5 or 3 of 5 as you open them. I think that would have brought a beginning and end to the list of objectives in the beginning. I know I forgot most of them or didn't have the time to read them in the beginning. So having updates would have been nice.
The zombies were fairly easy to handle because of the open spaces so the action can be stagnant at times. Also depending on player positions you may only have a small trickle of zombies actually come at you. This can slow down the gameplay and loose your attention.
The map did keep me entertained. It was a casual game which does let you explore more. There were a couple areas that get you thinking how to advance, but once you figure a few tings out, you pretty much know what to look for and do to complete the map.
Any map that can be beat, should be beaten at least once. So I would recommend any zombie slayer to check it out. It may have limited replay value, but you'll have some fun figuring it out.