Hi jonnyboy,
Hopefully you’ve had the chance to read the mattress shopping tutorial here which has all the basic information, steps, and guidelines that can help you make the best possible choice.
Post #2 here and the more detailed posts and information it links to have more information about safe, natural, organic, “chemical free”, and “green” mattresses and mattress materials that can help you sort through some of the marketing information and terminology that you will encounter in the industry and can help you differentiate between them and answer “how safe is safe enough for me” so you can decide on the types of materials or components you are most comfortable with having in your mattress. These types of issues are complex and are generally specific to each person and their individual sensitivities, circumstances, criteria, and lifestyle choices.
I certainly think highly of TMASC and they are exceptionally knowledgeable and helpful and are a member of this site but there are also some local options that may be worth including in your research as well. The better options and possibilities I’m aware of in the Greater Vancouver area (subject to the quality/value guidelines here) are listed in post #2 here.
Essentia isn’t an “all latex mattress” so hopefully you aren’t excluding an entire category of mattresses based on your experience with one mattress that includes memory foam in the top layer. You can read some of my thoughts about Essentia and some of the misleading claims they make and some forum discussions with them in this thread and this thread and posts #3 and #4 here). Needless to say I would be very cautious here.
I would be very cautious about using other people’s reviews or experiences on a mattress (either positive or negative) as a reliable source of information or guidance about how suitable a mattress may be for you or the durability of a mattress and in many cases they can be more misleading than helpful because a mattress that would be a perfect choice for one person may be completely unsuitable for someone else to sleep on or vice versa (see post #13 here).
There is also no “standard” definition or consensus of opinion for firmness ratings and different manufacturers can rate their mattresses very differently than others. Different people can also have very different perceptions of firmness and softness compared to others as well and a mattress that is firm for one can feel like “medium” for someone else or even “soft” for someone else depending on their body type, sleeping style, physiology, their frame of reference based on what they are used to, and their individual sensitivity and perceptions. This is all relative and is as much an art as a science. There are also different types of firmness and softness that different people may be sensitive to that can affect how they “rate” a mattress (see post #15 here).
When you can’t test a mattress in person then the most reliable source of guidance is always a more detailed conversation (I would avoid email for anything more than single sentence or “yes or no” questions … see here) with a knowledgeable and experienced retailer or manufacturer that has your best interests at heart and who can help “talk you through” the specific options they have available based on the information you provide them, any local testing you have done, and the “averages” of other customers that are similar to you. They will know more about “matching” their specific mattress designs to different body types, sleeping positions, and preferences (or even to other mattresses that they are familiar with) than anyone else.
There is also more about the different ways to choose a mattress (either locally or online) that is the most suitable “match” for your specific needs and preferences and how to identify and minimize the risks of making a choice that doesn’t turn out as well as you hoped for that are involved in each of them in post #2 here.
Phoenix