Hi tj6575,
While sister companies, their line-ups are separate, as are the “feels” they strive to achieve. Their goal is not to duplicate. I’m not sure how “interesting” that is 
, but there wouldn’t necessarily be a reason for all divisions under the Brooklyn Bedding umbrella to make a blanket substitution of one layer for another with the introduction of one new comfort material.
This is a thinner layer of soft polyfoam that is used in quilting layers that is used to affect the surface “feel” of a mattress. There is more about quilting foam and other types of quilting materials in post #12 here.
Yes, there would be a difference between both models, as they use different componentry and all of the layers of a mattress work together to achieve the overall comfort and support. The old BME had a 6" 2 lb polyfoam core, with 2" of Dunlop and 2" of Talalay on top of that, with thin polyfoam in the quilt. The Ultimate Dreams 10" latex you’re referencing uses a 6" 1.5 lb firm polyfoam core that is convoluted on top, above which is 3" of Talalay latex and then the 1.5" of Hyper Flex plush polyfoam. The old BME was available in three different firmnesses (as is the new version), and the Dreamfoam 10" Ultimate Dreams latex is available in 4 different firmnesses.
Phoenix