You'll get varying opinions, but using aftermarket springs will accelerate the wear on your OEM struts. Some may last years, others may be shorter, depends on roads, mileage, and how aggressive the springs are. Many go to coilovers as 1) install is easier (spring does not need to be removed from strut) 2) no premature wear on struts 3) ability to fully control height/damper 4) oem struts/springs can be swapped in at a later time.
It ultimately is just a decision where everyone must weigh out the pros and cons, with the pro for springs of course being less up front cost. Not sure on your make or model, but we have an opened box set of Eibachs here that are brand new we have on special if interested.
