Hi PantherFans,
The information you would need to assess the quality of all the materials in a mattress and make sure there are no “weak links” are in this article and the guidelines I would suggest using are in post #4 here.
With the Restonic I would want to make sure you have listed all the layers and to know the thickness of the quilting. If it was 2" or more then I would want to know the type and quality of the quilting material as well. I’m guessing that the memory foam is 7.0 lbs (not 70 lbs) which would be a high quality material. Assuming that you have listed all the layers, the quilting is less than 2", and that the memory foam is 7 lbs then there would be no weak links in the mattress.
With the Health Care Mattress I am guessing that the 35 lbs means 3.5 lbs which is on the low side (under 4 lbs) but would be more acceptable in a low budget mattress and I would also want to know the density of the other foam layers as well.
Phoenix