A stiffer frame transmits more of the shock load to the arm than a more flexible frame. A stiffer frame provides a more uniform ball response across the entire string plane. A larger frame generates more power. A larger frame is more resistant to twisting. A larger frame has a larger sweetspot.
Larger frames break strings sooner due to the string lengths.
Longer frames have higher swing weight than the same frames that are shorter hence the longer frames are less maneuverable. Longer frames generate more power than the same frame that is shorter.