Car: 2006 Chrysler SRT8
Join Date: Apr 2007
Thanked 1,991 Times in 1,800 Posts
My experience has been Eibach springs and KW coilovers. Both had higher spring rates as do most, if not all, aftermarket kits. Anything that lowers the car will have a higher spring rate, i.e., a stiffer ride. I agree with your mechanic. The stock struts and springs will provide a better ride. If there is a good aftermarket stock replacement and you want to maintain the ride you have, go with those.