The optimal position for the neck during rest is what experts call the “neutral” position. This is when that natural curve of the neck is at the perfect and comfortable angle, so as not to overly bend or compress the joints. For this ideal alignment of the neck to occur, it’s best to find one that is thick enough to allow your head to rest gently and evenly within the “neutral” position.
There are very few foreseeable issues with this choice. One of the few complaints is that it may take a while to get used to. Being that memory foam is quite a contrast to traditional feather pillows, uncomfortableness is very common for the first week or two. However, once surpassing the threshold of the first few uses, the pillow becomes quite enjoyable.