According to The Gentleman's Companion vol. 2 by Charles H. Baker Jr. (1939)
"Doctors still thought that a lot of yellow jacket malaria cases came from drinking water and swamp mists. The couldn't turn off the swamp water mists but they knew that diluted alcohol was a disinfectant agent against germs. So they put a little rum in their boiled drinking water. This tasted pretty bad so some bright citizen squeezed a lime into the thing, and added a little sugar to modify the acid. Ice made from distilled water took the topical heat off the thing. The 2 originators were my friends Harry E. Stout, now domiciled in Englewood, NJ and a mining engineer associate Mr. Jennings Cox. Time: Summer of 1898. Place: Daiquiri, a village near Santiago and the Bacardi plant, Cuba. Hence the name "Daiquiri."
I've tried many variations on quantities and either aged, light or dark rum. It really just falls into what your personal preferences are. I like the aged and light rum variations with same ratios but at 2oz, 3/4oz and 1/2 oz. Another example is that Robert Hess calls for this ratio but inverts the simple syrup to 3/4oz and lime to 1/2oz. Whether Difford's is the best recipe, again, is a matter of taste. Cheers.