I had an acdf surgery at c5-c6 which failed to fuse and I had to have a posterior neck fusion. 
I spent 2 years sleeping with a neck brace. I tried every pillow imaginable and tried memory foam
Mattresses and none of them worked. 
The GhostBed and Ghaot Pillow have helped me tremendously. I no longer need my neck brace to sleep since using the mattress and rrhe pillow.