Hi Beekeeper,
You are the only one that can feel what you feel on a mattress and there are too many unknowns, variables, and personal preferences involved to use a formula or for anyone to be able to predict or make a specific suggestion or recommendation about which mattress or combination of materials and components would be the best “match” for you in terms of PPP (Posture and alignment, Pressure relief, and Personal preferences) based on specs (either yours or a mattress) or “theory at a distance” that can possibly be more accurate than your own careful testing or personal sleeping experience (see mattress firmness/comfort levels in post #2 here).
If you are undecided then the “most common” choice would be to choose the medium but if you call and talk with them on the phone then they will be able to provide you with some guidance about which of their firmness choices would have the best chance of success. In the end when an online company has a free return policy then there is little risk in testing the mattress in your bedroom instead of a showroom so it’s really a matter of making a “best judgement” choice and then letting your body tell you how it feels when you sleep on it.
In general terms most foam mattresses that are in a suitable firmness level for the person sleeping on it don’t have or really need edge support. If you sit on the very outside edge then you will sink in more deeply than you may be used to than you would with an innerspring mattress that has edge support although it will also depend on the firmness level you choose. Even with sitting on the very outside edge though you won’t “bottom out” but if you sit back towards the middle of the mattress a little more so your weight is more evenly distributed then you would sink in much less (a few inches). For most people this isn’t an issue with a suitable mattress and it’s just a matter of getting used to sitting on the edge a little differently.
While the best source of guidance about whether any support system will be suitable for a mattress is the manufacturer or retailer that sells it … any support surface that is strong and stable enough to support the weight of the mattress and the people sleeping on it, has a flat support surface with minimal to no flex under the mattress, that provides some ventilation under the mattress, has good center support to the floor (to prevent sagging in the middle), and where any “gaps” in the support aren’t too large so that the mattress won’t “sink into” any gaps in the support surface will be fine.
If you are using 2x4’s on a bedframe that has a center support beam with support to the floor and the 2x4’s are attached and stable and not subject to sliding and there are only 3" gaps in between then then you should be fine. Depending on the finish of the 2x4’s I would probably put some type of cloth on top to prevent any splinters from damaging the mattress cover.
Their mattress was only launched a little over a week ago so it’s too soon to have any feedback on the forum yet (although there will be some soon) but I would also be very cautious about using other people’s experiences or reviews on a mattress (either positive or negative) as a reliable source of information or guidance about how suitable or how durable a mattress may be for you 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 either in terms of suitability or durability (see post #13 here).
Having said that … you can see some comments about the #BestMattressEver in post #3 here and as you can see it would certainly make a great quality/value and very durable choice.
Phoenix