The quality of the mattress varies from the number and composition of the layers in it. When choosing a mattress, you should take into account what is most comfortable for you to sleep on. If you have slept on a mattress with a wire core and it was comfortable for you, you should decide for that variant again.
The most common difference is in the hardness of the mattress itself, where those with a wire core are generally softer, that is, more elastic. This mattress model is the most sought after, it is used for French beds and models used for everyday sleeping. With such mattresses, it is important that the core is lined, as well as that it has several different layers besides the core.
Wire core means that there is a thick wire that runs along the edges of the mattress on the top and bottom. The wire core is much more durable and withstands higher lateral pressures. The layers arranged over the core can be made of different materials. Each additional layer gives the mattress different properties.
Avoid mattresses that only have wire over the core and two layers of ordinary thin sponge.