Hi ignacio001.
Welcome to our Mattress Forum! 
Sorry to hear that your Avocado mattress is not a good fit for your needs. Some good local testing can give a better sense of the many different types of materials and components that are used in mattresses and some reference points about the types of mattresses ( see this article) and general firmness levels you tend to prefer which can help you narrow down your choices regardless of whether you end up purchasing locally or online.
Typically, reviews or other people’s experiences in general, won’t tell you much if anything about the suitability, quality, durability, or “value” of a mattress for any particular person (see post #13 here ), and I’d recommend to avoid considering them as a reliable indicator of the appropriateness of any particular product for your needs. You can always do a Forum Search here to find any comments and discussions about any of the beds you mentioned.
I’m not sure what you’ve read since you found the site but just in case you haven’t read it yet … the first place to start your research is the mattress shopping tutorial here which includes all the basic information, steps, and guidelines that can help you make the best possible choice … and perhaps more importantly know how and why to avoid the worst ones and learn just enough to recognize a product using better quality materials or a retailer that is knowledgeable and honest so that you may trust the information you’re presented.
Two of the most important links in the tutorial that I would especially make sure you’ve read are post #2 here which has more about the different ways to choose a suitable mattress (either locally or online) that is the best “match” for you in terms of “comfort”, firmness, and PPP that can help you assess and minimize the risks of making a choice that doesn’t turn out as well as you hoped for and post #13 here which has more about the most important parts of the “value” of a mattress purchase which can help you make more meaningful quality/value comparisons between mattresses in terms of suitability (how well you will sleep), durability (how long you will sleep well), and the overall value of a mattress compared to your other finalists based on all the parts of your personal value equation that are most important to you (including the price of course and the options you have available after a purchase if your choice doesn’t turn out as well as you hoped for).
While again nobody can speak to how any specific mattress will “feel” for someone else or whether it will be a good “match” in terms of comfort, firmness, and PPP because this is too subjective and relative to different body types, sleeping positions, and individual preferences, sensitivities, and circumstances and you are the only one that can feel what you feel on a mattress … outside of PPP (which is the most important part of “value”), the next most important part of the value of a mattress purchase is durability which is all about how long you will sleep well on a mattress. This is the part of your research that you can’t see or “feel” and assessing the durability and useful life of a mattress depends on knowing the specifics of its construction and the type and quality of the materials inside it regardless of the name of the manufacturer on the label or how a mattress feels in a showroom or when it is relatively new so I would always make sure that you find out the information listed here so you can compare the quality of the materials and components to the durability guidelines here to make sure there are no lower quality materials or weak links in a mattress that would be a cause for concern relative to the durability and useful life of a mattress before making any purchase.
Once you’ve had the chance to read through the information provided and have more specific questions then I or any of the Expert members of the site would be happy to assist you.
Phoenix