I've used a few. They are very good quality filters, maybe even a little over-built. I'd feel quite comfortable running one for a long OCI with a synthetic, or leaving one on for 2 with dino as I was doing. They are also definitely over-priced, even when I used to find them on sale at $2 off. I never see them on sale here anymore. I tend to use cheaper filters now and change them out with every oil change.