Personally, I don't have any trouble hitting moving targets at 4000-5000 meters, but I've been helping out some newer players and squaddies who don't GV and it would be nice.
Typically, we just up in the TA, drive 3-4K away from each other and start shooting....it'd be nice to have a set of targets we could both shoot at to help explain ranging, deflections, and long range shooting especially.
Thanks for the input guys, and I'll be sure to DL that terrain and give it a try.