Yeah, the Denalis have it (autoride suspension) in 2011.  I've heard the compressor kick on when I start it.  Yeah, I'm sure that's the way it is on this rig...nice stuff to have...expensive stuff to fix.  I was already wondering (not that there's anything wrong with it now) how much my "Infotainment System" would cost to replace.  Easily $1k I'm sure.