I bought the full OEM set (rotors/pads/sensors) because I knew my pads were very worn at ~24k miles or so. Replaced the pads, but I checked the disks and I had only used up about a third of the rotors (about 3 years in). Kept the rotors and sensors for the next change of pads. No issues at all. Brakes work perfectly. That was almost two years ago. It should be another two years before I need new pads since I now put only about 5 miles per year. I'm at under 31.5k miles now. I could maybe even get a third set of pads out of the rotors, but that's definitely pushing it, IMO, and I'd also risk potentially ruining a good (and expensive) set of OEM pads prematurely.