Hi RohitK89,
The density of latex is a “comfort spec” and isn’t particularly important because when you are testing a mattress in person careful testing and your body will do a better ob of telling you whether a mattress is a good match for you in terms of PPP. With polyfoam and memory foam density is a “quality spec” and is important to know because it’s the single most important spec that determines the quality/durability of the material. There is more about the specs of the materials and components in a mattress that you would need to identify any lower quality materials or weak links in a mattress in this article but both of these are a high quality and durable material. You can also add a topper to a mattress that has a single 6" core if you need a softer layer on top for additional comfort or pressure relief.
This isn’t accurate information because you won’t find any 2 lb natural latex (it would have a much higher density). This would be a spec that would be more typical of good quality polyfoam … not latex. Having said that … there are no lower quality materials or weak links in the mattress. You can see some of the typical densities for 100% natural Dunlop in different firmness ranges in post #2 here.
There is more about the most important parts of the '“value” of a mattress purchase in post #13 here that can help you make more meaningful comparisons between mattresses. Only you can decide which one is the best match for you in terms of PPP or the other parts of your personal value equation that are most important to you but both of these use high quality materials and none of them have any weak links in their design so they would all be a durable choice.
If you were to add a latex topper (in a suitable firmness level) on top of the 6" core at Dixie Foam then you would have a more similar comparison between the two but the Room & Board also uses a wool quilted cover which would be more costly and would help regulate temperature better than a thinner or non quilted cover (see post #6 here). There is also more about the different types and blends of latex in post #6 here and more about the differences between Dunlop latex (in the Room & Board mattress) and Talalay (at Dixie Foam) in post #7 here but both are high quality materials and the choice between them would be a preference choice not so much a “better/worse” choice. The Room & Board mattress and I believe the Dixie Foam mattress are also two sided as well (see post #3 here) NOTE ADDED: Dixie Foam is now a member of this site as well.
Phoenix