There must be a difference between glass tops. Our salesman took a cast iron skillet and banged it down on the stove top and slid it around and abused it mightily and nothing happened to that top. I chop and slice on it and it has never marked for me and I've had it 12 years. I clean it with soft scrub and a lite green scratcher (not the dark green). Never had a problem. It stays with the house when it sells but I'm looking at the same stove for my new house.