Hello Douglas,
Mike here, same as "Mike Warren" on British Militaria.
Have this for you from Walsh's "Modern Sportsman's Gun & Rifle" 1882

I find my old(er) eyes like the "full sight" better. I do usually put the front bead center on the bull and have a bull that just a hair bigger all around than what the front sight subtends. Helps me center the bull.
Certainly faster aiming in game shooting the "fine sight" is out of the question, off the bench maybe OK.
…..your milage may vary

- Mike