I sleep on futon, as in two thin pads of cotton and wool batting spread over thin wooden slats, NOT an American-style couch/bed combo with a thick lumpy cotton mattress. The slat base is necessary to provide some airflow underneath, since we have a hardwood floor and not tatami in that room.
I haven’t slept on a standard bed in about 20 years. I had a high-end air mattress for a while after I moved out of the house. As a student, portability and cheapness won out. Disadvantages: noisy (especially when <ahem> entertaining company) and required a quilted base layer to prevent lying in sweat. Pretty soon after graduation, I moved to Japan, where I’ve been living for over a decade. Western-style beds are becoming more common now, but futon were still the majority when I first came, and I personally think they’re best for sleeping. Tatami are more comfortable than floor slats or platform beds for the underlying sleeping surface.
I never wake up with a bad back or tweaked neck except for when I go back to the US to visit relatives and have to sleep on a too-soft mattress with too many pillows. I absolutely think a futon or something like it is the best surface for sleeping on. If you want a more conventional look, a platform bed is ideal. If I ever manage to get enough capital together to move my family back to the US, I will either be bringing our futon with us, or will find a suitable replacement from an American source.