Hi bghouse,
Probably not a lot because there are a wide range of hotel mattresses. They would tend to be in a middle range though (not too soft and not too firm in either the comfort or support layers) so that they match a wider range of people “on average”. They often have a topper or bedding package as well that will change how the mattress feels and they tend to be in better condition than the mattresses most people sleep on at home (they aren’t used as much as a home mattress and are replaced more frequently). In many cases it’s the “anything is better than my mattress” syndrome if the mattress at home is not in good condition. Many people will find that purchasing a hotel mattress that they slept well on doesn’t translate very well into their experience at home even with the same mattress. You can read more about hotel mattresses in post #3 here.
I would also keep in mind that your experience may be from twisting something or straining a muscle because it came on so suddenly and it may be an idea to give it a little time before deciding what to do. Pain in your upper body or neck can also be connected to a pillow and it’s not uncommon at all for a new mattress to need a different pillow to maintain good alignment for the head and neck.
The previous link I posted has my thoughts about using a topper with a mattress that is too soft and some of the options that may be worth trying but if you are using a topper to add more softness to a mattress that is already too soft then I would make sure you have good return options available because the odds of a long term “fix” would be low.
Phoenix