Several years ago I bought a Beautyrest firm pillowtop and it remains the best mattress I have ever owned.  The pillowtop gives 2-3" and envelopes you and the firm keeps you from sagging.  Brilliant.  My new Harmony Lux Coral is listed as firm pillowtop and in no way resembles the other mattress.  It is just firm.  The pillowtop gives maybe 1/2", it's so little I can barely measure it.  And with that hardness comes concentration of weight, whereas the other mattress gets rid of pressure points by spreading your weight along your entire body.   I don't think the mattress is defective in any way.  I just think the description of it is completely false.  When I lie on it it feels like a plywood box with half an inch of padding.  It's THAT firm.   Maybe if I hire a team of 10 year olds to jump on it for a week....