I almost always use a spoon because I almost always add too much milk. I feel like using a fork is more dignified. But when is mac and cheese dignified?
My rule: if I eat it out of a bowl, I use a spoon. Off a plate? Fork.
Why? The spoon is curved and allows you to scrape all the goodies off the curved sides of the bowl. The fork has a much flatter edge that more closely matches the flatness of the plate.
I eat mac and cheese from a bowl, therefore… spoon it is.
burgoynealexburgoyne 
fork all the way, although when I am really hungry I use a spoon because I feel like I can shovel it in my mouth faster.
I almost always use a spoon because I almost always add too much milk. I feel like using a fork is more dignified. But when is mac and cheese dignified?
My rule: if I eat it out of a bowl, I use a spoon. Off a plate? Fork.
Why? The spoon is curved and allows you to scrape all the goodies off the curved sides of the bowl. The fork has a much flatter edge that more closely matches the flatness of the plate.
I eat mac and cheese from a bowl, therefore… spoon it is.