Got your thread going didn't it !!! Have worked and had experience of three types of aircraft with separate rest areas.
DC 10 :- Rest area, in lower galley, consisted of triple seat and guess what... blankets!! Noisy, in the way of normal galley activities, and altogether unacceptable for long/short periods of rest.
B767 :- Front right side partition off with small door access. Bunk with room for one ( poss two !!!) Positioned next to galley again, No means of blocking light out other than ineffective blinds. Annoying noise from cabin temp sensor fan positioned inside area.
Royal Air Force V.I.P transport aircraft :-
Sumptuous double bed, quilt filled with duck feathers, soundproofed with fully stocked bar. Private bath with own W.C
If you want to reduce Human Factors with Long Haul flying, go for the latter option.
If you are going to do it.... do it well.