Myself using Sleepycat Mattress & for d same ordered White Willow Butterfly Pillow. I'm System Admin with More pains for Neck & Shoulders.
1. My shoulder & body going inside Matress (Memory Foam) due to which the gap is long between Neck, Shoulders & Pillow . It is not comfortable, getting some pains with it for long stretch between Neck And Pillow.
For, me my hands not fully fixing in Back side resting position. Pillow size is bigger than my hands.
2. Pillow Memory Foam is little bit Hard for my Head and it cannot press memory Foam deep inside while Sleeping.
3. It was Awesome and excellent for Sides & Back Sleeping 100/100 for these.
Straight Sleeping position Neck Height placing, should be reduced to some extent. So, that it will be perfect for all Matress Users.
Pillow should be available in 2 Variants. One should be for Heavy Weight Heads,Broad Shoulders with Big in Size & 1 for little Weight Heads & Small Shoulders with some small In size.