Hey gobanana,
Welcome to the TMU forum 
! Thanks for your question and for your patience, apologies for the delayed response.
Congrats on your progress, sounds like you are doing a good job of combining site searches with store visits, a sound way to begin your mattress comparison process. For other consumer subscribers who may be starting their own mattress selection research, I recommend a read-through of the Mattress Shopping Tutorial: How to look for and find the best mattress…For You, a detailed article covering the 5 steps involved in making the best quality/ value choice.
Generally speaking, tight top mattresses outsell pillow top models on the upper end of mattress offerings where customers prefer a “firmer” feel.
The “materials” reference indicates a marketing story where the manufacturer is primarily using natural materials in the mattresses.
The Ideal Mattress website states that they are a “direct-to-consumer mattress manufacturer specializing in custom made organic mattresses.” While the site gives a breakdown of all their organic components and certifications, there is no specific component listing of the Crescendo hybrid, as you mentioned earlier. You may want to contact them directly, either through the factory or one of their showrooms for answers to those questions. If you do visit one of their showrooms, feel free to share your experience here, would be interesting to hear about that.
This means that there is a layer of latex, either Dunlop or Talalay, probably less than one inch in thickness that has been through a perforation process of having holes punched through the latex, thus making it more “breathable”.
As Dream Time Mattress is factory direct, you can ask them about a latex build, if that’s your preference. I’d prefer not to comment on whether latex is the “better” of the foam materials, as this is more of a “feel” issue, part of your individual "PPP/ Posture and alignment, Pressure relief, and Personal preferences. Here are some thoughts Phoenix has regarding Latex Mattress Choices you may find useful, should you want to research that topic further.
Again, if you visit either Dreamstar or Dream Time’s showrooms, please share your research findings with the TMU Forum, would be curious to hear about your experience. BTW, do you have any updates on your research thus far?
Thanks,
Sensei