Have a half, restless night with the pillow behind me ... the first impression was really great, you is definitely comfortable, it feels so good (because I'm happy I did it higher with 5 liters filled-fits perfectly! ) ... but - it's incredibly cold !!! It really amazes me that that was not often criticized :-( I am side sleepers, while the shoulder / neck pushes up on the lower, water-filled part ... even though I had also the original Mediflow pillowcase over I kept the cold hardly ... So even my warm Beaver pillowcase over it ... all in vain, the lower side flows with the water so cold out that I could not stand it after a few hours and my old pillow vorkramte again. Too bad as I said, it is very comfortable on, and if you rather sleep in tends to perspire which is perhaps the Sexy on the pillow - For me, that pillow is unfortunately nothing and will be returned to Amazon :-(