OEM front struts last along time, often the life of the car and unless they're noisy, binding, bouncing or leaking, there's nothing wrong with them and no good reason to replace them IMHO.

Rear shocks (except Nivromats on multilink cars) don't last as long and they tend to leak in time causing a bouncy ride.

I think alot of people spend money needlessly on replacement struts and shocks when the originals aren't yet bad. Don't believe the adds that places like Goodyear, Firestone, etc all try to hype and OEM Volvo suspension parts are ALOT better than those found on domestic cars.

If your struts/shocks are still good now, I'd leave them alone.