The issue is whether more customers would respond to the term "polycarbonate unibody" or "removable battery". My contention is that most customers won't know what "polycarbonate unibody" means. My contention is that they will understand what "removable battery" means.

This is an elementary marketing question. The answer is obvious.

BTW: What is polycarbonate and why is it good? No fair looking it up.