Hi Dave88LX,
Part of the problem with hotel mattresses is that they don’t disclose the density and quality of the foams they use and in most cases they are lower quality and subject to foam softening and impressions. One of the first “rules” of mattress shopping is to make sure you know the quality of all the components and layers in the mattress. A mattress is only as good as its construction and materials … especially in the upper layers (the comfort layers) and if you buy a mattress that uses lower quality foams or materials in the upper layers especially (which is common to most of the major brands) then foam softening and breakdown will lead to the loss of comfort and support much more quickly and this isn’t covered by a warranty. I would avoid any mattress where you have no way to make meaningful quality and value comparisons because the risk of a much shorter useful lifetime is much higher. There is more about hotel mattresses in post #3 here.
The first place to start your research is post #1 here which is a step by step buying guide that has all the basic information, steps, and guidelines that can help you make the best possible choices … and avoid the worst ones.
I’m not sure where you are in Maryland but there is also a Baltimore list in post #2 here although much of it duplicates the DC list you linked.
Once you’ve done the basic reading … if you have questions along the way feel free to post them here … and welcome to the forum 
Phoenix