I originally rated this product as a 2.  The power boil burner had only high and higher.  After 3 tech support visits, I was told it was operating correctly and rated the product.  I subsequently offered to pay for complete replacement of the burner AND controls.  The tech on the fourth visit looked and said "that isn't operating correctly", and replaced the burner and controls.  The power boil burner now operates as expected, and is fully functional, with a full range of heat controls.  I am now very pleased with the features, operation and the functionality of this range.  I don't think I could have found a better one for my needs.