[hancock1701]

I think springs normally don't need to be replaced unless they are rusted or broken. My Honda and Boxster, both have passed 140k miles, but the springs on both cars are quite good, no sign of wear or anything weird.

I would check all the sway bar bushings and sway bar links for play and looseness, since they're there, not very expensive, and new ones will give you tighter suspension feel.

EDIT: In fact, I just got a box from ECSTuning with four stabilizer links and four bushings. I got those because I'll replace them "while I'm in there" replacing the rear trailing arms.