Hi 6488,
I’m glad you found us. As you can see from post #1 here (which is the starting point for any new mattress search) … it’s fairly simple to know the quality and value of a mattress once you know how so from this perspective you can set your skepticism aside. This is the reason why knowing all the details about what is in your mattress is so important because you don’t have to “believe” anyone about the quality or value of a mattress because it’s self evident.
As you can read in post #2 here however … the quality and value of a mattress has little to nothing to do with how suitable it may be for the specific needs and preferences of a particular person. The mattress you purchased from OMF is an example of this because they are higher quality and better value than almost any mainstream mattress but as you know the choice you made wasn’t suitable for your body type, sleeping positions, and preferences. This is the most difficult part of choosing a mattress. A mattress that is “perfect” for one person may be completely unsuitable for another and this has nothing to do with its quality. Making the most suitable choice for your specific needs and preferences is always the biggest challenge once you know to only deal with manufacturers where the quality and value of their mattresses is known and “transparent”.
I would normally suggest some local testing first if any mattress you are considering uses materials that are unfamiliar to you so that at the very least you know in general terms how a certain material feels and responds. I would also suggest local testing as a reference point so that you can make better choices about the comfort level that is best for you as well (they give you a choice). While they will help you with this based on body type and sleeping position “averages” … in the end only you can make the choice or know if you made the best one. If you are uncertain about which choice to make … then it makes sense to choose a model that allows you to make layer exchanges in case you make the wrong comfort choice.
So while their quality and value is self evident (and like all the members of this site I consider them to be among the best quality and value in the country) … your comfort choice is just as important a part of the purchase as the quality, and value of the mattress.
Hope this helps a little with your “skepticism” 
Phoenix