Hi msprotege,
There is more about the most important parts of a mattress purchase in post #13 here that can help you compare them based on the criteria that are most important to you but I would certainly consider any one of them.
The Novosbed Harmony is an approximation of the Sealy Optimum Inspiration, the Select Foam Cirrus Prima is an approximation of the Tempurpedic Cloud Prima, and the Christeli Danieli is an approximation of the Tempurpedic Rhapsody Breeze so all of these are very different mattresses.
None of them have any weak links in their design in terms of the quality/durability of their materials but I would test each of their “equivalent” mattresses locally to see which one is most likely to be the most suitable choice for you in terms of PPP (Posture and alignment, Pressure relief, and Personal preferences) because this is the single most important part of the “value” of any mattress purchase. I would also make sure you have a more detailed phone conversation with each of them (see mattress firmness/comfort levels in post #2 here) so you are in a better position to decide which of them would make the final choice that is “best for you” (see post #2 here).
Phoenix