Hi kbayless,
Welcome to the Mattress Forum! 
You’re welcome!
I’m not sure what you’ve read since you found the site but just in case you haven’t read it yet … the first place to start your research is the mattress shopping tutorial here which includes all the basic information, steps, and guidelines that can help you make the best possible choice … and perhaps more importantly know how and why to avoid the worst ones.
I [quote]
would welcome insight/considerations for pros/cons between the Alexander Hybrid and the Alexander Latex Hybrid mattress
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Here are the specifications of the Nest Bedding Alexander Signature Hybrid:
1.5" Soft Quilted Cover
2" 3.5 lb Copper Infused Memory Foam
2" of our SmartFlow Foam (1.8 lb porous, punched polyfoam)
7" 5 zone pocketed coil unit with Edge Support.
While I can’t speak to how a mattress will feel for someone else … in terms of the quality and durability of the materials … the 3.5 lb memory foam would be generally be a slightly lower quality/density and less durable material than 4 lb memory foam and would be “on the edge” or slightly less than the minimum foam density guidelines I would normally suggest so I would be cautious for anyone that is in a higher than average weight range or BMI.
The innerspring is zoned which would affect the feel and performance of the mattress and may make it more suitable for a higher percentage of people but there is also a reduction in the type and amount of specialty foam materials in the comfort layers above the spring as well so the mattress would have less of a memory foam “feel” with the thinner layer of memory foam and the more resilient “feel” of the polyfoam underneath it.
The soft version of the Nest Alexander Signature Series uses …
1.5" polyfoam quilted to the cover
2" 4 lb gel memory foam
2" 4 lb memory foam
3" 1.8 lb hole punched polyfoam
4" 1.8 lb polyfoam.
The medium version uses …
2" 1.5 lb. polyfoam quilted to the cover
4" 4 lb gel memory foam
1" 4 lb memory foam
2" 1.8 lb hole punched polyfoam
4" 1.8 lb polyfoam
The luxury firm version uses …
1.5" polyfoam quilted to the cover
2" 4 lb gel memory foam
3" 1.8 lb hole punched polyfoam
4" 1.8 lb polyfoam.
All of these are good quality materials that would be suitable for more average weight ranges but I would be cautious for those that are in higher weight/BMI ranges (a BMI of 30 or more).
The medium version also uses a little thicker 2" quilting layer and I would normally suggest no more than “about an inch or so” of lower quality/density layers in a mattress and once there is about 2" or more of lower quality/density foam (less than 1.8 lb density for polyfoam in a one sided mattress) or “unknown” materials in the upper layers of a mattress then the odds of premature foam softening and breakdown would be a little higher.
Assessing the durability of a mattress is just a matter of knowing the density of the memory foam and polyfoam in the mattress and comparing them to the quality/durability guidelines here.
All the layers and components in a mattress affect the feel and performance of all the other layers and components both above and below it and the mattress “as a whole”. In terms of “comfort” firmness and PPP the only way to know whether one design of the Alexander would be better or worse for you would be based on your own personal experience. For some people it may be a better “fit” and for others it may be worse depending on their body type, sleeping style, and their own specific needs and preferences.
If you can’t test the mattress in person then the most reliable source of guidance is always a more detailed phone conversation with a knowledgeable and experienced retailer or manufacturer that has your best interests at heart and who can help “talk you through” the specifics of their mattresses and the properties and “feel” of the materials they are using (fast or slow response, resilience, firmness etc.) and the options they have available that may be the best “match” for you based on the information you provide them, any local testing you have done or mattresses you have slept on and liked or other mattresses you are considering that they are familiar with, and the “averages” of other customers that are similar to you. They will know more about “matching” their specific mattress designs, options, and firmness levels to different body types, sleeping positions, and preferences (or to other mattresses that they are familiar with) than anyone else.
Their detailed knowledge of their mattresses and how they fit with different body types and sleeping positions along with your feedback from local testing, a customer base of many people that they can use as reference points, and any exchange, return, or any options they have available to customize a mattress after a purchase can help lower the risk of an online purchase. These online retailers or manufacturers can also be a good “value reference” for local purchases to make sure that if you are paying a “premium” for a local purchase (in exchange for the kind of “in person” guidance, service, and value that comes with dealing with a local retailer that can help you make more “accurate” choices that you have tested in person) is not too high.
Nest Bedding has a great return policy that lets you test the mattress in your bedroom instead of a showroom to find out whether it’s a good “match” in terms of comfort, firmness, and PPP with little risk outside of the time you spend sleeping on it or returning it should that be necessary.
As you may know, Nest Bedding is a member of this site which means that I think highly of them and I believe that they compete well with the best in the industry in terms of their quality, value, service, knowledge, and transparency.
I look forward to learning about your progress.
Phoenix