Hi CentralPA,
Does this have a zip cover? If it does it would give you the chance to re-arrange or exchange layers which can be very helpful if you need to fine tune the mattress.
[quote]10" profile with 3 3" latex cores with a mattress topper 3" latex. This could contain 2 Wool and cotton covers depending on the topper and cover used for the bed. My concern with this option is you have cotton wool cover, then latex in the topper, then wool and cotton cover again, then the 3 layers of latex. After researching a lot I have concluded that this will definitely change the feel of the bed.
Would a wool and cotton topper with a cotton cover on the mattress be better possible? This would also give my wife and I a different way to try the latex bed if we need to change things up.[/quote]
This would be a preference and there really isn’t a way to predict which one would work best for you. It’s true that using a quilted cover in a mattress and having a separate quilted cover in a topper will put more material between the latex layers which would feel different from either having the same layer inside the mattress or using a stretch knit cover but only you can decide on which one is better for you. In terms of quality they would both be good options but only your own testing and experience can assess which one is a better match for you in terms of PPP.
A separate topper on a mattress can also respond more independently than the same material inside a cover where it’s more “restricted” in how it responds so like a pillowtop it can feel a little softer than using the layer inside the cover.
If the 4 layer mattress has a zip cover then I don’t think either one would be more durable because either the topper or the top layer in the mattress would generally be the first to soften and both could be replaced without replacing the entire topper. A separate topper may be a little bit less durable than the same layer inside the mattress because it will be a little more subject to compression forces when you sleep on it because it acts more independently but I don’t think the difference would be enough to make it an issue with your choice.
If I’m understanding you correctly then both of your choices would have the same 12" of latex and the only differences would be that in one the top layer was inside the mattress and in the other it would be outside the mattress and that with the topper option you would have a separate cotton/wool quilted cover around the topper (so it would probably be a little more costly).
I would make the choice based on your preferences and which one feels and performs better for you because in terms of durability they would be very similar.
This thread and post #3 here has more feedback about the same idea (a separate topper vs the same layer inside the mattress) and some of the differences in how it may feel.
Phoenix