Hi jenjrev,
The most accurate way to choose a mattress / topper combination is always personal testing on the specific combination that you plan to use. To the degree that something else that you buy is “different” from what you have tested you introduce variables that can sometimes produce unexpected results because each person can have very different perceptions.
Having said that … the smaller the difference between what you have personally tested and what you buy the less these variables or unknowns will be.
I would also keep in mind that both thickness and softness act hand in hand and will affect the feel and performance of a topper.
Any softer material will also be less durable than the same material in a firmer version but I would also keep in mind that latex is also more durable than other materials in a similar softness level so the idea of softer latex being less durable is really only relative to firmer latex (and of course the other factors involved in durability here).
I’m assuming that you were testing a 2" PLB topper (not the 3") and if this is the case then my comments about the topper I mentioned previously would probably be the closest “firmer” choice … ie.
If the Essence and a 2" topper seems to be the most suitable for you, then I would probably choose to buy 2" of 19 ILD in the knowledge that it will be similar to but a little bit firmer (the same approximate firmness as the top 2" of your mattress) than the softer PLB topper. I would make sure that you spent enough time on both options to have good confidence that one or the other was better for you in terms of PPP..
There is also not a lot of difference between 19 ILD and 21 ILD and for most people this is below their ability to detect. I would also keep in mind that many manufacturers (including mattresses.net) have products available that are different from what they list and it’s always a good idea to call and talk to them to see what they would suggest.
The Seven Comforts has boxed sections so the latex wouldn’t shift as much as a pillow and doesn’t need “adjusting” but it’s also not as resilient or the same feel as a solid latex layer and it will impress under your heavier parts to some degree although it’s also easy to fluff back up (like a featherbed). Because of all the preferences and variables involved … your own experience is really the only way to know for sure (just like you are not a fan of shredded latex pillows that some others may love) but in general I would tend to stick with toppers that you were more familiar with and you know in your own experience work well unless you are OK with the added “risk” of trying products that are not familiar to you. No matter how much others may like the Seven Comforts (including me) or any other product … if the feedback and discussions about it doesn’t seem to “attract” you or give you enough confidence that it would be a good choice then as a general guideline I would stick with materials that you know better and you know will likely work for you based on your personal experience.
I would choose based on your actual testing in combination with the information in post #2 here (and the posts it links to with more subjective guidelines and sources).
I would make this type of decision based on your level of confidence that your testing is a good indicator of your long term satisfaction with the mattress/topper combination. In terms of materials … they are both good quality materials so there would be no real concern there but there is little chance to make further adjustments (other than bedding and more toppers) if the combination doesn’t work for you.
There are other certainly other options that have more flexibility in re-arranging or exchanging layers that can be “fine tuned” more than the Essence / topper which may give you the ability to “zone in” more accurately on a specific feel or combination of pressure relief and alignment but in the end it is always your own confidence that will be the deciding factor. I would certainly talk with some of the options that are available to you in post #21 here regardless of what you end up choosing because your conversations with them may be the biggest part of choosing the “best” direction to go. Without talking to them you are really going by “theories” that are outside your actual experience and this tends to lead to much higher levels of uncertainty.
Assuming that your testing is “accurate” … sticking with what you have tested as close as possible is also more important for people that are more sensitive to small changes in a mattress than it would be for people who have a very wide tolerance range for pressure relief and alignment that is suitable for them and can be quite happy with a wider range of mattresses. The more you are in the “princess and the pea” range and the less you are in the “I can sleep on anything” range the more value I would place on careful personal testing.
Phoenix