Solid surface is very eay to repair. If you have a crack in marble or granite, a skilled expert will fix it. He will use coloured grout cement or some chemical to make crack invisible to human eye. How much soever you try, after a while join will be visible. it will start collecting dirt inside. Although, we have team members who do marvelous job in Italian marble flooring, but still you cannot match Corian finish.
Once you fix a crack in Corian, it becomes seamless, like brand new.
If there is a small crack on solid surface after years of usage, it is easier to fix then you thought. A small piece is cut & removed from that area with crack. Then a new piece of same size is pushed inside this cutout. Adhesive like material is used to stick whole thing. This adhesive like material is made up of material of your base solid surface.
It means if your corian kitchen countertop is made up of solid surface XYZ, this adhesive has XYZ material. After this there is regular cleaning & buffing process. Once done whole thing looks seamless. No joints, No lines. After buffing ( kind of light polishing) whole surface looks brand new. No other material can give you such a seamless finish. Working with material is easy & less messy then most other material options.