In case this helps any- I am hour glass shape, 123 lbs. Hubby is 5’10" and 185 lbs. Side sleepers, but occasionally on backs. He likes kinda firm and I like a tad softer. I have lower back and shoulder aches and need the mattress to support our bodies for years to come.
The Dreamfoam hasn’t been sold for a year yet (less than half that) so you won’t have any customer experiences after a year but it will have the same durability as any other mattress that uses the same materials and construction no matter who makes it.
There are many factors and variables involved in the durability and longevity of a mattress (and you can read about the many factors in post #2 here) so predicting a specific number of years for any particular person is not really possible. What I can say though is that latex is the most durable of all the foams and in an apples to apples comparison … a latex comfort layer will last longer and stay more consistent than any other type of foam.
This information along with any preferences you have and any feedback from local mattress testing will be valuable when you call and talk with Chuck about your choice of firmness level of the latex comfort layer. The manufacturer themselves knows every layer and component of their mattresses and how they were designed to interact and also has experience and feedback from a large customer base which can help them use other peoples body types, sleeping styles, and experiences that may be similar to yours to help you with your choices.
The online manufacturers that are members here are very good at working with their customers on the phone to help them make the best possible choice.