Hi geremiaunit,
Both of these mattresses are very similar in design but there are a few differences between them that may affect your choices.
Foam Sweet Foam (FSF) uses organic Dunlop for their Dunlop layers while SleepEZ uses 100% natural Dunlop (although they will provide organic Dunlop as an option). There is more about organic latex in post #6 here.
They also have slightly different exchange and return policies (see here for FSF and see here for SleepEZ).
As you know both of them are members of this site which means I think highly of them and I believe that both of them compete well with the best in the industry in terms of their quality, value, and service.
There is more about the most important parts of the “value” of a mattress purchase in post #13 here that can help you make more meaningful comparisons between mattresses.
There is also more about the differences between Talalay and Dunlop in post #7 here but the choice between them in any of the layers in a mattress would be a more a matter of preference than a “better/worse” choice.
When you have eliminated all the options that don’t meet your criteria and you are down to finalists that are choices between “good and good” and there are no clear “winners” between them then your final choice (see post #2 here) would be a matter of “best judgement” based on your more detailed conversations with each of them and all the objective, subjective, and intangible parts of your personal value equation that are most important to you (including things like delivery times, return or exchange options, prices, the importance to you of buying a mattress that you can test locally, any bonuses that come with the mattress etc). You are in the fortunate position that either of them would most likely be a great quality/value choice that you would be happy with.
Phoenix