Hi Lumpy,
Thanks for sharing their replies to your question … I appreciate it 
There is also a little more information about how Tuft & Needle, Casper, and Leesa compare that is more focused on the type and quality/durability of the materials in post #3 here.
Dreamfoam is a little different from any of these because they are an actual manufacturer that makes their own mattresses and not a “reseller” and they have many mattresses available in a range of different materials and styles and firmness levels … not just one. Many of them also allow you to customize the firmness level before a purchase and with some of their mattresses that have exchangeable layers you can also customize the firmness level after a purchase as well.
How they compare with any of the “one choice fits all” types of mattresses would depend on the specifics of the mattress you are comparing and the parts of your personal value equation that are most important to you.
Phoenix