If we would like to compare most similar arms, BX165L and BX200L main difference is different reduces ( to be more precise reduction raio). This causes diffrent allowable moment of inertia at wrist section and max torque wrist can generate.
Also max rotational speed of each axis is diffrent.
Ceratainly those parameters must be taken into concideration in robot firmware but I guess none ordinary user have acces to those parmeters