I've had my Corian for four years now and have had no problem with scratching. I do not put hot pots on it and I don't cut directly on it. I had laminate before, and I didn't do those things with laminate, so it's not a problem for me.
The appeal of quartz I just don't get, although I know it's very trendy now. To me, it's nowhere near as attractive as granite and it's more expensive. I've got granite in my bathroom and the amount of effort required to seal it is nothing. I think it's funny that people make a big deal over that.
For cost and feature comparisons, see
http://www.oneprojectcloser.com/kitchen-countertop-material-comparison/