Reflectors are better than nothing. If states require them, use them. However, I don't think most states specify what type of reflectors: CPSC, DOT, or tape. There are arguments that CPSC reflectors suck (I agree) and you are better off using DOT grade reflectors.

My state requires a front light, and a rear red light or reflectors. And also reflectors on the pedals unless they are on shoes or ankles.

I've taken off the sucky CPSC reflectors and have reflective tape everywhere on my bike: frame, cranks, wheels (not on the brake rim surface). Of course, I have front and rear lights with my reflectors on my shoes.