Today I installed the 70 lb/in springs received from Zelioni for $65 ($30 product, $35 shipping) to replace its normal USA/Europe 90 lb/in spring. In the process I learned a lot. Upon disassembling the spring from the shock I made some measurements that surprised me. Modern high end shocks use pressurized nitrogen, duh. In the Zellioni this gas pressure results in a roughly 27.5 lb/in spring rate, by my measurements, for the shock without any spring! So in reality, the stock USA Zelioni spring rate is 117 lb/in and my new 70 lb/in spring really results in a actual spring rate of 97.5 lbs/in which is about 17% lighter than the original rate, rather than the 22% expected if only considering spring rate. At any rate, had I realized this bit I would have ordered the 65lb/in springs, but that is a small difference. Check out the pics and come back to read my driving assessment in a few days. There is a post here that describes the importance of the nitrogen pressure parameter:
http://www.rzrforums.net/suspension/10042-check-your-nitrogen-level-shocks-here-how.html