Arvin Meritor, makers of legendary RydeFX shocks, is pretty pumped about its all-new RydeFX Air 2.0 springless shocks (OEM equipment on 2008 Polaris Dragon models).
These actually use nitrogen instead of air and have two separate pressure chambers allowing for soft initial stroke and a firmer resistance to bottoming at full compression.
The use of nitrogen makes sense because air shocks are prone to pumping up from heat and air expands, increasing the overall spring rate and degrading ride quality.
The RydeFX design using nitrogen is more temperature stable and dual chambers provide vastly improved calibration possibilities across a broad range of rider weights and ridingstyles.
These are a full pound lighter than conventional coil-over shock dampers.