I replaced an old cooktop with this one.  It was an exact fit, so no alterations were needed at all.  The big burners on this cooktop heat water much faster than my old one.  I also like the fact that there is a light that comes on under the gas knob when the gas is on.  Sometimes with my old one, you could not see the flame if it was on very low, and the burner did not get turned off.