The burners work well and the 3 different burner ratings provide flexibility.  The metal grates raise the pots 2 inches from the glass plate, which is inconvenient for shorter people.  The metal grates stay hot for a long time which can be a safety hazard.  The black glass top is exceedingly difficult to clean.  The knobs are flimsy.  This unit replaced a 2006 GE Profile (central downdraft) yet installation was a nightmare: (I) the rectangular exhaust fan outlet is far too low (5" from bottom of cabinet) and only 4" from the cabinet door, so I had to design and build my own sheet metal duct to connect the fan exhaust to the vent line; (2) the unit is not as deep as its predecessor, so the rectangular hole in the granite was a bit too big (leaving a constant worry that the glass may crack).