Huh. Website shows a 162" track is all there is for "new" in the mountain sleds. Otherwise the new SRX looks kind of cool in the black paint, but it's a short track only and all they did was stuff the apex motor in the nytro chassis by the looks of it. Not sure why they didn't do the same thing for the mountain Apex though. Can't click on any of the models for more info though for some reason...
http://www.yamaha-motor.com/sport/products/modeloverview/cat/2010/61/model_overview.aspx
http://www.yamaha-motor.com/sport/products/modeloverview/cat/2010/61/model_overview.aspx