ess only has this warning on 2 of their 4 supercharger kits.this one,for example,is rated up to 775 hp,makes 585 hp,and is suitable for all e90 m3's from '08 on-
http://www.esstuning.com/products/E9...er-System.html
i discussed this rod bearing issue with 2 friends of mine who are bmw techs.they don't believe the earlier e90 m3's have a rod bearing problem.they just said the newer ones are tighter,and better suited for supercharger application.
if ess offers a kit capable of 775 hp on an 08 or an 09 with the original rod bearings,the motor must be pretty sound