The actual Ford coils themselves (the electronic part) lasts for a loooooooooooong time. Its the boot and spring that usually go bad and they can be replaced as Stray said. The springs/boots on a COP setup are basically like doing the wires on a 98-down. You are replacing the connecting end and the rubber boot in both cases.
2000 Mustang GT Steeda #0048 34k miles. 99 Cobra 4V swapped, FTBR IRS swapped, exhaust, tuned by James Gordon.
Just because I give you advice, doesn't mean I know more than you. Its just means I've done more stupid ****.