As far as replacing the air springs, its about the same effort as steel springs, if not easier as you can deflate them. There are a few air hoses to hook up that, if not done right, can leak. And then there is the nitrogen refill. The front shocks are integral with the air spring, the rear shocks are more conventional and can be replaced separately. The big difference is parts cost, where steel springs are less than $100, air springs are more than $1000 each.
These air springs are made by continental which has a good reputation for building durable springs.
2011 Grand Cherokee Overland V8, 2009 Liberty Rocky Mt V6, 2000 Grand Cherokee Laredo I6, 1979 CJ7 I6 Quadratrac