We,ve just bought a Re-ly-on memory foam mattress. It felt more responsive when there were no sheets on it, and I only had to use one memory foam pillow which we chose in the shop - I tried it out at home when it was unwrapped with the same result. However as soon as a matress protector and sheet go on top, I need an extra thickness under the pillow. The husband is getting more pain in his left shoulder than he usually gets (sadly on the side where he doesn't snore) since getting it (only been on it 3 nights). I have told him it may get better as he gets used to the matress. He is reluctant to remove the protector as he doesn't want to get ithe mattress dirty.
I have not noticed if I am warmer or not. My feet and lower legs still remain cold all night which make me wonder if that is why I maybe sinking too far in the middle, as it is supposed to be heat responsive, and therefore my head and shoulders are at a more acute angle to the bed, hence the need for extra pillow height. I do not feel I am sleeping "straight".
The saving grace is that I am feeling les creaky, so it must be helping - I feel no pressure point pain anymore - whooppee - but am worried about the husband relating his pain to the mattress, when he was suffering before but not to the same degree.