Just finished it as well, great surprise at the end, hopefully setting up part two :)
Overall, great feedback. I'd never really flown the Huey before this, and I felt that this did a great job of pushing development, making it difficult, but not impossible. Some of the missions took me a few tries, some due to the mission, some due to my own stupidity.
Echo the comments about long distance legs being monotonous, but I guess that's reality. More interaction with Atc would be cool, as well as more frequent landings or more challenging landings (rooftops, constrained spaces). The weather variances were just right, fun to do low vis flying.
Hopefully you guys are working on something for NTTR, or even the Normandy map, this is by far the best campaign I've done. Well done!