It's not slight, it's almost half of whole milk, and about 50-60kcal per 100ml comparing to semi skimmed. When I drink coffee with milk I have about 100-300ml a day, it can be a difference between putting on weight and maintaining. For me I don't notice a difference in taste, especially if it's all frothed up. Can see the point if it's for cereal though or just drinking straight
My clearly UO as per this thread is that opinions about which food is better is not really an opinion, just personal preference