The only time I heard about low level formatting was when my first hard disk (Quantum 1.2 GB) developed problems which I could not resolve by formatting. I called a technician who after elaborate attempts told me the only possibility is to try low level formatting which is risky. I agreed and of course it was futile and I had to buy my second HDD (Samsung 3.2GB) same day itself.
It is unheard of nowadays.