Air Adjustable Shock Absorbers - Any Good?

[mickburkesnr]

I was watching one of the new Wheeler Dealers where they picked up an old truck and fitted air adjustable shock absorbers. I didn't think they existed, but on the show (at least) they looked like they worked really well. They had filled up the back of the truck and it started to sag so they inflated the shock absorbers and it leveled the truck out again.

At some point the shock absorbers on my Toyota Corolla are going to need replacing as the front one's rubber has already split. As I'm going to be in the market for some shock absorbers (as I may do front and back) I was wondering about whether these air adjustable shocks are any good? Would I have to expect any problems from them? I don't want to put them all the way round, just at the back so that if I have more than me in it (which happens often) I can level the car out.