Some opinions:
Stainless steel will dent and is noisy, but it doesn't chip. It water spots badly and if you are the fastidious kind, it will drive you crazy.
Porcelain over cast iron is quiet, but it can chip; waterspotting is not obvious. The chips can be repaired if not too large. What makes a porcelain sink turn dingy is using abrasive cleaners like Comet. The best cleaner to use if you are starting with a new sink is some powdered laundry detergent and bleach; apply with a patio salt shaker. Go easy; you won't need much!