After some inquires about this matter I done some years ago, and also recently, as user I got this conclusion about trademarks and types of mattress is spanish market:
– Option A) 100 % NATURAL latex. Be careful that’s not the same that 100 % latex. Ivorimatex (it’s not easy to find) and Relax have models in this way. Pay attention on its section size (from 15 to 20 cm) and its density.
– Option B) Viscoelastic. Tempur (expensive) and Relax (more cheap and correct). Pay attention on its density, pressure and/or temperature adaptability and its viscoelastic section size (from 5 to 11 cm, or all the mattress could be enterely viscoelastic).
– Option C) Bultex. I don’t know about any trademark.
Depends on its density and behavior, a latex mattress could be stronger than a viscoelastic and, vice versa. First you have to test and decide between one and other kind of product that you prefer.
You ALWAYS should test the mattress before. Big stores like El Corte Inglés, surely would be more expensive, but could be useful in order to get the possibility to see and test in shop the product before buying there or anywhere else.
See you.