Good info in the article, and after using the airbags for a year, I can attest to their durability and usefulness when the JK gets loaded with gear or towing a trailer with 350 pounds of tongue weight. However, the installation instructions in the article show way to many steps, as I just performed steps 8-11 with the jeep sitting in normal form. Didn't even jack the jeep off the ground to unload the rear, and the airbag still slipped into the spring easily. Ran the air hose, mounted the valve and I was ready to rock and roll. Total install time was about 20 minutes.
Even if you don't tow a trailer, I can see the airbags being useful when the JK is loaded with camping gear, so worth the $90 investment.