Modern air shocks are both strong and very progressive. If an air shock is used on a constantly progressive design then the design will become incredibly progressive, to the point that you will not be making use of the full range of travel under normal riding. The Pyre and Rune use a slightly progressive to slightly regressive design to optimise pedal performance and suspension 'feel' for trail riding. The result is almost like having a pedal platform between 25-50% the way through the travel where the suspension will have minimal 'bob' even under aggressive cranking on those pedals. (just as any pyre rider how well the bike pedals even over rocky terrain and up tech rooty sections). The Rampant has a purely progressive leverage as a 4X racer wants to bike to work like a hardtail until he needs the suspension to take a big landing. So the leverage is designed to be very progressive and stiff.
The next graph is a graph showing the forces required to compress the suspension at the axle. (although perhaps not too clearly, sorry!) These are not preset by any means as the shock setup controls this. However these were taken with the average settings for an air shock, so that you can make it more progressive feeling, or more linear as you desire.
You can see here that the Pyre is the most linear of the designs, to give a smooth feeling suspension for all day rides both up and down hill.
The Rune has a much more progressive feel than the Pyre to cope better with taking bigger hits (small drops, rock gardens etc), and will over that more bottomless plush feeling.
