Hi Gomdori,
You’ve probably already read this but just in case some of the forum threads that talks more extensively about mattresses and children are linked in post #2 here. They include many links to more information and various options, and sources.
All of the choices you are looking at though would be among the top choices I would also consider and I think highly of all of them. Two of them are manufacturing members of this site and the other (Berkeley Ergonomics) also makes high quality mattresses. When you are down to these kind of final choices that are between “good and good” and there are no cautions to consider … then of course the objective comparisons (the type of materials and components in each mattress and the “raw value” of each of them) along with the more subjective and intangible comparisons between each retailer or manufacturer is the only meaningful way to compare them and each person may have a different idea of what is most important to them. You are in a place where all of them would meet your three criteria and would be a very suitable choice. A mattress purchase includes the mattress itself of course but also includes the benefits and options that come with dealing with a particular retailer or manufacturer before, during, and after the purchase which is just as much a part of the “value” of a mattress purchase as the mattress itself.
I should also mention that all of these will also be durable enough that when your toddler becomes older and begins to develop that any of these choices would be very suitable for adding a good quality topper that could meet the comfort needs of older children as well although if everything else was equal I would tend to lean towards all latex vs an innerspring in terms of durability, performance, and “value”.
So I would trust your instincts and your “gut” with your final choice and be very comfortable knowing that none of these are bad ones and will meet all of your criteria. It’s just a matter of deciding which one best meets your personal value equation.
Phoenix