I purchased this pillow after trying one at my chiropractor's office. I purchased the gentle firmness instead of the standard firmness. The middle neck support is designed for sleeping on your back and it is great. Each side is designed for side sleeping. The problem with mine is that one side is soft and comfortable and the other side feels quite firm.  My chiropractor told me the pillow could not be returned once opened but I recently contacted the company (Core Products) and they told me that it could be returned because of the satisfaction guarantee. I will let my chiropractor know about the policy.
Assuming the different firmness issue is a defect, I'm hoping to get another one.