I have tried down, memory foam, and synthetic down pillows, but none compare to my Hullo. I sleep on my side and back and I love how this will confirm but still be supportive. You adjust the firmness desired. I also appreciate that is does not get hot causing sweaty neck as I had with memory foam pillow and yet it stays supportive unlike my down pillows. I get the best sleep.
You do need to get used to the noise of shells moving but now I do not notice and my husband never noticed. There is no funny smell like the memory foam pillow.
Being able to take shells out of case and air out in a box when I wash the cases is nice and eco friendly.