Yep, it's air. It handles everything great and ramps up real nice. I'm running quite a lot of sag for a 6" bike and it still handles the bigger hits very nicely. I'm very impressed with the air. I could have traded straight across for a DHX 5 with ti spring but I chose to keep the air shock.... so that's saying something.
They are all the exact same frame.... they are all slopestyle slayers... that's what the ss means. This one is the best model though, aka the "427" part.