Hi Mueller,
The White Dove latex mattresses also have some polyfoam and quilting fiber in the mix so this may be part of the reason for the impressions although 9 years of comfort is better than a lot of the mattresses people are buying these days 
My thoughts about some of the iComfort lineup are in post #11 here. While they certainly have a nice showroom feel … I think there is much better quality and value available.
I have somewhat mixed thoughts about Boyd. They are marketed to retailers primarily as a high margin mattress and promote that profit margins of 60 percent and higher (meaning that 60 percent of the sale price is profit). They are made to look good but use lower priced materials including Chinese suppliers.
They are also active in the Specialty Sleep Association environmental and safety program which assigns levels to a mattress based on how “green” it is and the degree of testing it has passed. Level 2 is the step where all polyfoam products (and viscoelastic or memory foam is a polyurethane product) has to be CertiPur certified (although the Boyd Site says CertiPur testing is part of level 1 … perhaps because this is the level they have achieved … but this is not the case).
They also have a tendency to misrepresent their products (for example calling high density polyfoam that is engineered to feel like latex “engineered latex” to add perceived value to the mattress when it isn’t latex at all) although many of their mattresses do have some latex. Their gel memory foam is also the particulate type which is my least favorite (they tend not to be as durable as the gel infused type). Since level 1 talks about disclosing all the materials in the mattress … it would be interesting to know if this includes density information about their gel foams and base foams and I would also want to know specifically if it made by a CertiPur foam manufacturer.
They are also all over the map with their pricing in various outlets with some charging way too much, boyds online direct outlet charging less (although the names are different) and various “discount” or “liquidation” outlets charging even less yet (a google search will bring up lots on places like Amazon and eBay). They are popular with outlets that like to sell mattresses that look like they are more expensive than they are.
So overall I would want more information about the materials in their mattress (including density of the foam) but some of their models would could represent better than average value … at the right price.
There are several good options in Kansas City and post #2 here should help.
Phoenix
PS: I finally was able to post this because the system didn’t like it when I used percentage signs for some reason and it took about a dozen edits to figure out why I was getting an error message … but it]s done now