Just read above. Right now I have somewhere between 25-30,000 miles on them. Stock springs. Also, how long would they last with Ground Control coilovers?

I would say the AGXs should last at least as long as OEM struts, but it depends on what damping setting you have, If you gor GC's for example, you would need to stiffen up the damping settings, making the AGX's work harder, therefore shortening its life span. so in short no conclusive answer from me.