The principle IMO opinion is a very good one .... the added air pressure into the shocks relieves some of the weight off the leaf packs and assists with trim ... air, even when under pressure in a system like this, compresses further quite smoothly, so the additional 'hardness' of the shocks comes without the jarring that is associated with harder hydraulic shocks. The hydraulic component of the air shock is assisted, improving efficiency under load, ..... and they are adjustable from inside the cab, a definite plus.
My only concern however would be as Missouriman mentioned is the ability of the shock mounts to withstand the extra stresses that they were not designed for. I'm quite sure that they can take a lot more hammering than standard shocks can deliver, but how much more. You might find that there is no problem, but what if it let's you down along the road. It might be an idea to get the air shock suppliers' opinion and look at possibilities of strengthening the mounts.
The other possible downside may be the cost ... supply and fitment with the possible beefing up of the mounts initially, along with the maintenance replacement thereafter. It's my understanding that the rubber boots / seals for the air ram component of the shock are susceptible to damage and wear, requiring replacement before the life expectancy of the hydraulic component. There is also maintenance of the compressor unit and air lines to consider. Then there's the cost of total shock replacement when they've seen better days, which would be considerably more than standard units.
All things being considered, I still think that they are a viable option with real benefits.
Don't have a clue what it cost yet however, seems it's made by same guys as OME.
Dis dan n DATSUN 
