Hi britas,
You are in the enviable position of having done some good research and have reached the point where you have eliminated all the worst options and are choosing between good and good. Some of these have bigger differences (such as wool or no wool in the quilting, thicker or thinner comfort layers, choices between blended, natural, or "organic Talalay or Dunlop in the comfort or support layers, all latex vs a latex hybrid, higher or lower costs for a similar design, differences in return or exchange policies etc) but assuming that you are confident that all of them would match your needs and preferences (or could be adjusted to do so) then my suggestions would be more about how to choose than what to choose and would be similar to post #2 here and post #3 here and post #2 here.
FWIW … it took me over 2 weeks to make all the “tradeoffs” that it took to make a final decision between some final choices that all seemed great for different reasons and in the end it was relatively unimportant factors in the overall scheme of things that tipped the balance. At that point the overall differences in “value” were so small and subjective that even small things seemed more important than they were.
Phoenix