Autoride is 2 things. First, it offers active damping control via the electrical connector on the shock. Secondly, it does auto leveling in the rear via height sensors, a compressor and the air bags built into the shocks.
You can get a pair of shocks for $400 from Arnott, with a lifetime warranty. I am considering this for my '05. I have also thought about adding some "universal" airbags instead and plumbing the stock air lines to them to get the same auto-leveling feature.
Before you start spending money, check out the rest of the system. Many of these have blown up compressors, which is also a high-$$ item. I already solved this one by sourcing another Arnott-made compressor from a Buick or something. I did this because I was able to get it for $30, while most that came from a GMT800 are hundreds, even though they are the same basic construction. I was able to take apart both compressors and come up with a working one that mounts to the truck. Then I tested it by turning on the truck. When I jack it up by the hitch, the compressor turns off, so I figure I'm good to go once I get the shocks.
If you run standard shocks, you lose the electronic damping control. Some people claim that's an improvement, but I'm skeptical because our Yukon XL rides like a dream.