The single biggest drawback to AirBag Jacks is that they lose their lifting power/ability as they expand - less surface area is contacting the ground and the load. What this means is - A bag rated at 34 Tons inflated to about 3 inches will only lift 30 Tons, inflated to about 5 inches will only lift 25 Tons and inflated to about 9 inches will only lift 15 Tons.
Note the sample chart...

First off, look over the chart from a standpoint of what you NEED to do - How much weight do you need to lift and how far. Find where these points intersect on the chart THEN look at the AirBag Capacity LAST.
For example:
If you have to move 40,000 pounds 6 inches your best bet is the 34 Ton model. Like this....

Everyday thousands of people are pumping hydraulic jacks through miles and miles of dead air before the load contact point is reached. Without too much effort AirBag Jacks can be shimmed, cribbed or in some way brought closer to the load so less dead air jacking is needed before contacting the load like these examples...
This Modular Home Builder sets his AirBag Jacks on an equipment dolley.

Here a 'Live' Polaris Rocket Motor is gently positioned for transport/assembly. Note the cribbing set underneath the AirBag Jacks...

Here, in a very unique application AirBag Jacks are helping to 'Turn' a slab in a limestone quarry. After the slab begins moving more bags can be slipped lower into the crack and provide more force as the inflated bags begin to lose their capacity. The company is saving both time and money with less waste, less manpower and faster jacking ability.

Finally, here AirBag Jacks are merely doubled up to get the lift and capacity needed to lift an open pit mining vehicle for maintenance. Once again, note the simple cribbing used to save wasted inches of jack travel...