I donated my '99 S70 to the local public radio station in July, after 21 years and 276,000+ miles of daily service. They got it with the original PS fluid. Everything was great on that car except the tiny leak in the head gasket and the CAT it poisoned...I’ve done a Magnefine on the return line of the PS systems on all three Volvos in my signature.
Did they help? Hard to say. They didn’t hurt.
All three have the original rack. The rack is crazy expensive and requires dropping the subframe to replace, so I wanted to ensure a long life for the rack. With over 265,000 on the high mileage one (the XC) I’m glad I installed the magnefine.