Hi brianwolf,
The first place I would start your research is the mattress shopping tutorial here which includes all the basic information, steps, and guidelines that can help you make the best possible choices … and more importantly know how and why to avoid the worst ones.
As you can see in the guidelines here … I would avoid all the major brands or any mattress that has more than “about an inch or so” of either lower quality or unknown materials in the comfort layers especially (which would include most of the Novaform mattresses as well) because they are much more likely to soften and break down prematurely which can lead to the loss of comfort and support much too quickly relative to the price you paid and would be very risky choices.
There is also more about the most important parts of the “value” of a mattress purchase in post #13 here which can help you make more meaningful comparisons between mattresses.
Phoenix