Nitrogen pressure change valving?

I was looking at this write up and they talk about depending on the nitrogen pressure you can make minor adjustments with the valving. It does not go into much detal. Can anyone tell me what less or more pressure will do to valving?
Link: http://www.off-roadweb.com/tech/0906or_powertank_nitrogen_shock_kit/index.html

Thanks

 

The recommended pressure for each brand of shock is usually best, however altering the pressure up and down will increase or decrease the amount of cavitation (vacuum bubble that forms behind the piston) leading to a slightly softer or firmer feel. The problem however is, too little pressure (i.e. less than 150psi usually) and the shock will fade and begin to malfunction. Too much pressure (i.e. greater than 300psi depending on manuf) and the seals may fail prematurely in addition to a potentially harsh ride. That's the simple explanation. Optimal pressure is the least amount that gets the Job done without fading or boiling the oil.

 

Thanks.