I did get the X-Reas suspension.. its standard on the CDN V8 Limited models.
When I test drove it I was very impressed, I drove a Sport with the X-reas with out air suspension..and liked it..just a little less.
I never tried one with out the X-reas.
So its hard to tell what its really doing for me, but based on how it works I like it alot. It makes a lot of sense. Wouldn't be surprised to see an adaptation on sports cars as well.