Air Adjustable Shock Absorbers: Any Good?

On an episode of Wheeler Dealers in the UK they fitted some air adjustable shocks to the back of a pick up truck in America. They loaded the back and adjusted the ride height of the vehicle with these shocks.

I wanted to know whether these were a good option for someone who will, at some point, need to replace the current stock absorbers in their E11 1998 Toyota Corolla? I only want to adjust the back, not the front.