We just gave it a try with Zipper5, and we thought it still could use a lot of work.
First off, the briefing. I see you've got it in the known bugs list, but why wasn't it implemented in the mission anyway? If you don't know how,
here's a good tutorial about it. Should be helpful.
To the mission itself... Well, right after it started, we had no idea what to do or what's going to happen until we discovered the commands in the radio menu. I hope you'll have a note about them in the briefing or, for now, at least a hint in the mission itself to advice the player to use them.
After some while of flying, above the supposed LZ, our chopper started to take some enemy fire from unknown location. The chopper then took off to the North and started hovering above some woods without moving. Knowing that he wouldn't go off anywhere from that position, we ejected the chopper in mid-air, without parachutes, causing fatal results.
We thought the mission was depended on the team leader slot or something like that (We only took the LMG and AT unit slots), so we then enabled all the AI and I became the team leader. But that same thing occured again, but fortunately the chopper yield to land when I ordered the team to dismount in mid-air. We then landed 1500m directly to the North of the first waypoint, way off the supposed LZ. Nevertheless, we continued on to the first objective and just when we arrived, I started to get some massive perfomance drop. I thought it was just my computer, rendering the buildings in nearby cities or something, but this occured permanently, even after respawning back to the home base. At this point, Zipper5 had to leave so I quit the mission aswell.
Does the mission have heavy scripts running or anything like that? I thought about that, because even Harvest Red the campaign, which is supposed to be really heavy, runs fine on my rig...
I hope you'll manage to improve the mission and sort out what I reported so far, so we can have a proper test of it.