Questions about Salus memory mattress

Hi, Iv'e got a question, I have ordered a Salus 'Memory pocket 2000' mattress, this was ordered from a local retailer, when we looked at it in the showroom It had on the label 70/75mm memory foam top with vertical ventilation and pocket springs. What arrived today was not what we ordered, this one was marked as a 'Latex memory pocket 2000' and the label description was 2.5cm latex, 5cm memory and encapsulated pocket springs. I didn't notice until delivery men had left. My question. Am I better off keeping this or accepting the replacement that has been offered (the originol ) I have searched for more information about this style of mattress but can find no answers, do you guys have the answer to this?

Sorry you won't/didn't get the sale but this Latex/memory combined thing appears to be new!

So your opinion on this could be invaluable to others. Many thanks Peter .