Welcome back EmiAldeer!
In 2022 King Koil announced a line of 7 ‘Re-Spun’ mattresses which use up to 50% of upcycled denim, to promote sustainability and reduce landfill waste. Unfortunately, details are scarce on the exact specifications of these mattresses; They contain natural and organic materials, with glue free ‘quad core’ microcoils and a ‘FlexECore’ innerspring. As you say, the salesperson told you the comfort layer is latex; Though their mattresses seem solidly built, the lack of transparency in materials and composition make it nearly impossible to assess how they would work for you and your partner in terms of support and comfort. If you do find the specifications, let us know and we may be able to comment further.
You and you partner both have lower BMIs; and as any mattress you choose will be unique to you, based on your Stats (height, BMI, sleeping position(s) and any underlying health concerns) - thanks for providing those! - and your PPP (Posture and alignment, Pressure relief, and Personal preferences), it all depends on how you and your partner feel on this particular mattress. It sounds like you prefer a plush firmness level, and microcoils…also, a tufted mattress will have a different, ‘tighter’ feel to it than a non tufted one . The Joma wool layer here provides breathability as well as a fire retardant layer, and is a common material in ‘natural’ and ‘green’ mattresses.
In general, you can compare the Mattress Specifications You Need To Know to the Mattress Durability Guidelines to see how certain materials hold up.
If you are looking for a more natural sleep system, many of the Trusted Members of the site carry latex and other types of natural and organic mattresses with microcoils and innerspring layers which you may want to review.
~ Basilio