I purchased this pillow system 5 years ago now. I have nothing but praise for it! My sleep quality with this system has improved 100% and had stayed at this level as long as I use it. I've been forced to go without it occasionally, and my sleep quality is terrible without it. No shoulder pain or numbness throughout the night. Acid reflux is a thing of the past. And the best part of all my obstructive sleep apnea is properly and safely managed without the need for a cpap. Im no doctor, but the monitor ring device i use to track my O2 levels doesn't lie. The only thing I've noticed recently is that this 5 year old pillow system is near the end of its life cycle. I will be purchasing a replacement soon! Thank you Medcline!