Flat or heaped? A spoonful of sugar

My dad always asks for two heaped sugars in his coffee. Is it worth it? How does it compare to a level spoon of sugar?

Initial tests:

Standard Teaspoon – mass of granulated sugar (nearest gram)
Level 5g
Heaped 7g

Medicine Spoon – mass of granulated sugar (nearest gram)
Level 6g
Heaped 9g

It looks as though heaping sugar on top of the spoon increases the sugar by a factor of 1.5 (or thereabouts). I now need to get into the science department at work to use a more accurate set of scales.

Is it worth asking for heaped spoonfuls of sugar. Yeah, go for it!