The performance of all clamps is identical, clamp size is dictated by your application.
You may encounter space limitations when trying to go around a cable, a conduit, or a pipe.
4” is the standard clamp, most widely used.
5” is becoming the new standard due to its ability to do everything that the 4” clamp does, plus being able to fully clamp around a 4” conduit.
2” clamp is useful when working in small spaces such as a street light post, an electrical cabinet, or other small pedestal or enclosure.