I have had a smooth top for almost 17 years. I have used it to can using a pressure canner. Also have slow simmered spaghetti sauce for canning for HOURS. I have not been ABLE to crack that top. I personally do not like the smooth top for cooking of any kind, but perhaps that's because mine is old. It holds the heat too long and there is very little control. I have abused it every way I can think of short of dropping my iron skillet on it (they don't recommend iron skillets either) and that thing just keeps going. I'm going to give up soon and just get rid of it and replace with a gas stove.
Just my personal opinion.