Our Nutrition and Wellness Educator, Donna Falconnier, has this to say: the basic difference is in the processing of the potatoes with the flake rehydrating faster than the granules. The term buds is a brand name for the granular type of instant potato. In nearly all recipes they can be interchangeable with out noticing a difference. Sometimes the flake will make a thicker product than the granular type so if you need to have a thicker product you may want to use just a little less water when using the granules. You will need to read the package to see what they consider a serving size. My guess is that it will be 1/2 cup for either variety since serving size for like products must be the same amount. You will then need to look on the directions and follow what they suggest for water and potato product to produce one serving per person or 1/2 cup.