Also, I think over the whole GRAW co-op campaign, there has been only about three or four really challenging missions. On the first GRAW, there was the Wharf map because when you went into the town section of the map you had the rebels coming from all that part of the map. So, you had to watch your front, back, below and above yourself. Then on GRAW 2 I think Caldera, Hideout and Swamp Airfield were the most challenging missions.
Caldera: objectives were spread apart and you had to split up to complete, but the downside was you could elimnate the rebels then go do the objectives. You didn't have objectives that were time sensitive.
Hideout: Here you had the same setup as Caldera but after you disabled the comms, you still had to clear out the remaining rebels in the compund. Here again, they could have modeled the objectives after Swamp Airfield objectives and had some type of vehicle come up if you didn't disable the comms or the rebels sounded the alarm.
Swamp Airfield: What else can be said about this mission, it is as close to perfect as you can get.