Both step drill bit vs knockout punch seems to do the same of making a whole in a metal box. The step drill seems to have the advantage of making several size wholes all in one bit. My questions is, What is the major difference difference between the two. Do we need both. Which do you prefer to work with.

Both a step drill bit and a knockout punch seem to be very similar, in that they both make holes in a metal box. 

The step drill seems to have an advantage, since it can make several size holes using a single bit. 

What are the major differences between the two?

Both step drill vs knockout punch seems to do the same of making a whole in a metal box. The step drill seems to have the advantage of making several size wholes all in one bit. My questions is, What is the major difference difference between the two. Do we need both. Which do you prefer to work with.

Both step drill bit vs knockout punch seems to do the same of making a whole in a metal box. The step drill seems to have the advantage of making several size wholes all in one bit. My questions is, What is the major difference difference between the two. Do we need both. Which do you prefer to work with.