I rather think pillows are a matter of preference. By preference, both my sons slept entirely without pillows into their mid-to-late teens, while my wife and I use one foam pillow (exactly like Dunlopillo but another make) each. You can recognise people who use two or more thick (e.g. feather) pillows stacked up because they have already developed the often-mentioned "vulture neck". Reading in bed is often the start of increasing pillow thickness. The salesman patter will try to persuade you to buy all sorts of things based on "scientific" logic but in the end you need to feel comfortable and be able to rest well and that may be a block of wood or a ball of twine - all up to you. Like sprung, soft beds (they always end up sagging like hammocks, no matter what the initial praise), pillows can be less than helpful to posture and skeleto-muscular wellbeing. To a certain extent, pillows may be purely a comfort-sop (like the comfort-rag), something to have against the skin and to cuddle. Note that, when you see people raised in the developing world, they have a posture to die for and are far more supple than we are. Note also that they sleep without pillows on very hard surfaces (no posture controlled springs, etc.) . Could there be a connection ?