I always tend to stick with OEM or equivalent myself. I had one co-worker who "upgraded" her plugs to some new pulstar plugs. Initially she was pleased with how much smoother her car ran and the mileage improvement as her old plugs were worn and required changing anyway. Within a month she had numerous issues where the engine would just die or run VERY rough accompanied with multiple check engine codes. Oddly enough none related to misfire or specific cylinders. After a visit to the dealership for work it was determined the pulstar plugs were at fault. Swapped out with new OEM style and all has been good. Only took $600 at the dealership to find that out.