Hi cownox,
Neck issues are often a pillow issue although of course there are other possibilities as well.
Some of the other possibilities that can affect how a memory foam mattress feels and performs when it is new (especially when it has high density 7 lb memory foam like the Regalis) are listed in post #2 here. I would probably wait a little longer before deciding to make changes since you still have lots of time left in your trial period. have you called them for any suggestions they may be able to make as well?
You can read a little more about making final choices in post #2 here. Your choices are all between “good and good” and they all have good quality and value which is all I can really speak to.
Given the difficulties you have had with making choices that worked out well for you … I would also consider the benefits of having more options and layers that can be exchanged or re-arranged which means the Alexis may have an advantage for your circumstances.
Phoenix