Hi Big D Buyer,
You can see my thoughts about them in post #9 here. A forum search on tempflow (you can just click this) will also bring up more feedback about them.
The main factor in the quality of a foam (quality as defined by durability) is its density so the 5 lb memory foam used in the Tempflow mattresses would be the rough equivalent in terms of durability to Tempurpedic. With memory foam … the additional benefits of higher density become much less once you are past about 6 lb density or so which means that 7 lb memory foam would not be that much more durable than 5 lb memory foam but there would be a little difference. The quality of their base layer is higher than Tempurpedic and of course they have also tested their Biogreen memory foam for VOC’s and will provide results to their customers which Tempurpedic hasn’t. The “feel” of one memory foam vs another would be a subjective preference although I can tell you that I personally like the “feel” of the Biogreen (we have one of their pillows) and there was very little to no odor when we received it.
There are many factors involved with the “value” of a mattress purchase depending on the criteria of your personal value equation that are most important to you and of course one of these is the “commodity value” of the materials in the mattress. Part of this would be the amount or thickness of the more premium materials in a mattress (such as the memory foam) so from this perspective the Eros has 4" of premium memory foam while the Grandis has 5" plus the memory foam in the quilting and the density of the Grandis is also a little higher so it may have a little better “raw materials” value but of course this is just one part (and arguably not the most important part) of the “value” of a mattress purchase. The Tempurpedic GrandBed has 7.2" of memory foam but of course the cost is also so much higher that it wouldn’t measure up to the other two you are considering by most people’s definition of “value”.
Phoenix