I've worked in one place where ALL the burgers, 4 oz, 8 oz, 12 oz, and 16 oz were pressed by hand. I currently work in a place where we have a press, and use it frequently as we only buy pre-formed patties for large functions. I've also use two metal pie plates with patty paper on the metal to keep them from sticking.
Personally, I like the hand-formed better.