The map places two teams facing off across a chasmatic gulf, with the bases perched high in the air on a pair of mountains. There's not much room for deuling, except for a small area under the bases. (The outposts from Katabatic) The vehicle pad is situated away from the main base, and there are enough inventories to keep a team-well supplied, along with sentry turrets at every entryway.
As said before, if you don't have a vehicle, you're either playing defense, or you're dead. Once, as a heavy, I accidentally slid down the side of my team's mountain: and once down, only a light with an energy pack can get up. Call for a ride, and if there are good teammates, they may pick you up: otherwise, you're stuck for good.
The bomber is going to be crucial, in Thin Air. The V-Pad is open, and my guess is that it will be down a great deal of the time. Just about the only hope for a team will be to run constant Shrike pickets, both offensive and defensive. Heavy Armors stationed along the top of the base would help as well, and keeping the turrets up is a good idea, too.
The flag is a bit hard to grab, much less to cap: first you've got to get your Shrike parked somewhere safe, and pray no one finds it and blows it up. Then, get inside the base.. all four entrances have Sentry Turrets guarding them, but if you go up the entryway chutes, you have a slightly better chance at dropping down on the flag. (Again, there's a turret guarding this area.. be careful!) With full-time flag D, with the base farmed out, I see it hard to cap period, and hardly even get a touch. If you grab the flag, tho', and make it out.. and if your vehicle is unmolested, and if you can drop to it, without pancaking the landing, and if you can fly back home without picking up a tail, then you're back free!
Playability is rather low, since you can't use your feet at all. Attention to detail isn't lacking too much, but then again, not much stands out, either. The balance is so far in favor of the Defense that you're going to need a coordinated assault, along with a personal guard, but that sort of coordination is rarely seen. It would be fun to see if it would work out, tho'. Item Placement is well done. I took a few points off for the many Sentry Turrets, but the Inventories are all where you'd look for them, and you don't have to go hunting for them when you need them. There are even a few on the roof for those Heavy Defenders! Mechanics I believe could benifit from making the hills climbable, and protecting the V-Pad a bit. As it is, not only is the cap hard, but you're forced to rely completely on vehicles.
If you enjoy flying, I honestly suggest this map. You should have quite a bit of fun dog-fighting it out high above the ground.. just hope that you eject over your own base!