Hi karminsknator,
Welcome to the Mattress Forum! 
You are correct that there is little if any meaningful information provided about all of the mattresses you mentioned, and as such I would tell you to avoid anything for which you can’t find out the information listed here, so you can compare the quality of the materials and components to the durability guidelines here to make sure there are no lower quality materials or weak links in a mattress that would be a cause for concern relative to the durability and useful life of a mattress before making any purchase.
Many of these mattresses are made by Zinus which owns the trademark for " real mattress in a box ". Zinus is a Chinese manufacturer that uses mostly low / mid quality materials although they are CertiPur certified. They are most commonly sold under many brand names in big box stores and elsewhere. Whenever you see “green tea” you can also assume the manufacturer is Zinus.
I would also read post #6 here about mattresses imported from Asia or China and which may have been compressed for long periods of time in either shipping or storage before being purchased and a forum search on Zinus (you can just click this) will bring up more information and feedback about some of their brands and mattresses. Being sourced in China make this somewhat of a risky purchase IMO, even if the mattress is “Made in the USA” but the componentry is from China.
Regarding reviews like these on Amazon and other sites, these or other people’s experiences in general won’t tell you much if anything about the suitability, quality, durability, or “value” of a mattress for any particular person (see post #13 here). I would ignore them completely.
If you’re considering a memory foam mattress online purchase and you want to make sure that you’re dealing with reputable vendors using quality materials, I would tell you to consider using the expertise of the site members in post #21 here, many of whom offer memory foam mattresses. 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. In addition to the online members of the site listed in the previous membership link … post #12 here has some of the better online memory foam options for those who are looking for a memory foam mattress.
Good luck, and let me know if you are able to find out any meaningful information about any of the other mattresses you mentioned.
Phoenix