I agree with the feet higher position in a nylon hammock, though in my woven mayan hammock (used indoors) I prefer head higher. The reason is, as was already stated, that I tend to slide down too much when my head is higher in a nylon hammock and I'm constantly having to push myself back up. In the woven hammock I basically stay wherever I lay, so I have more options and find that I prefer head up.
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