My neck had straightened due to repetitive motion/work injury, neck,shoulders , arms hands etc..
I tried many pillows and PT for many sessions.. & very good chiropractor with time away from work finally resolved most problems.. I had anterior spurs @ c 4/5/6 but nothing bony impinging nerves.

The contour pillows work well for me, the gel /memory foam one @ Costco is a good fit for me , I use the smaller side of the curve as the large side is too high for me.
Part if it is finding the one & style that fits best for you..