We have had this cooktop for only two weeks - have not used much yet.  For what we have cooked it has performed superbly.  However, we are bit freaked-out vis-a-vis the cost (over $750) and how delicately it has to be treated.  It seems rather silly to make a kitchen product that costs so much yet has to be cleaned using a special sponge and cleaner.  If you seriously cook then you may want to consider something other that a glass cooktop. We are afraid any little thing we do while cooking or cleaning will crack, chip, or scratch the glass.