I purchased a pair of these pillows after reading as many reviews as I possibly could - and I looked at literally dozens of other pillows before deciding upon this purchase. I am a side & back sleeper (mostly side,) and have THE hardest time finding the right level of comfort and support. I went with the "Firm" selection after reading the reviews. I slept on them exactly one night - they were extremely comfortable and I truly slept like a baby, BUT they were too high for me and when I woke up I had a really stiff neck that lasted most of the day. So the first set are now being used as "knee & body" pillows. I am hoping that eventually they will wear in enough that I could use them under my head. HOWEVER, they honestly were SO comfortable to sleep on, that I have gone ahead and placed a second order for the "Medium" firmness. I am looking forward to receiving these. I do consider them an investment, and if they are even half as comfortable as the firm density without giving me a stiff neck, then I will state that my rating will change to 5 stars.