Hi sliceoflife,
Assuming that the materials in a mattress you are considering are durable enough for your body type and meet the durability guidelines here relative to your weight range … the choice between different types and combinations of materials and components or different types of mattresses are more of a preference and a budget choice than a “better/worse” choice (see this article). The best way to know which types of materials or mattresses you tend to prefer in general terms will be based on your own local testing or your own personal experience.
Each mattress category can also include hundreds of different mattresses with a very wide range of different designs, different “feels”, different characteristics, and different firmness levels. Every individual layer and component in a mattress (including the cover and any quilting material) will affect the feel and response of every other layer and component both above and below it and the mattress “as a whole” so each mattress category will generally include some mattresses that have a design that will be a good “match” for you in terms of “comfort”, firmness, and PPP and others that use the same type of materials and components and are in the same category and may be just as durable but have a different design or firmness level that may be completely unsuitable for you to sleep on … even if it uses the same general type of materials and components.
Latex and memory foam are very different materials with very different properties but again the choice between them is more of a preference and budget choice than a “better/worse” choice. There is more about some of the differences between memory foam and latex in post #2 here. Some people tend to prefer the faster response and more resilient and “on the mattress” feel of latex and some prefer the slower response and more “in the mattress” feel of memory foam but again the best way to know which type of materials or mattresses you tend to prefer in general terms would be based on your own careful testing and/or your own personal experience with each material in a range of different firmness levels.
If you would like to do some local testing if for no other reason than to get a general sense of the types of materials and mattresses you tend to prefer (regardless of whether you end up purchasing locally or online) then if you let me know your city or zip code I’d be happy to let you know about any of the better options or possibilities I’m aware of in your area.
Phoenix