Hi Bhutain,
If the area sales manager can’t or won’t provide you with the density of the foam layers in the mattress then “quality” is just a meaningless word and he is just “selling” you instead of “informing” you.
I’m not so sure whether it’s your “best bet under $1500” in terms of the material value (there are some very good quality mattresses in this budget range) but it may be the best match for the criteria of your personal value equation which means it may be the best value for you. They are transparent about the materials they use so I would certainly choose it over the Stearns & Foster. The firmness of a mattress is completely subjective though and depends on each person’s body type, sleeping positions, and individual perceptions. There is no “standardized” firmness ratings between different manufacturers but when the same manufacturer “rates” their mattresses it can give you a reference point about the relative firmness of each of their mattresses. For most people their “Plush soft” would be softer than their “Luxury firm” which in turn would be softer than their “Firm” but these wouldn’t necessarily agree with the firmness ratings of other manufacturers. Your own experience will be the most reliable way to know if it’s a good match for you in terms of PPP.
Thanks for the feedback and congratulations on your new mattress 
I’m looking forward to your feedback when you’ve had the chance to sleep on it.
Phoenix