I recently bought a couch rom Ralph Lauren and it came with ultra blend couch cushions. The cushions started to flatten. I did;t know a whole lot about couch cushions. they are willing to replace the cushions for more firm cushions, however they do not have the two most firm cushions to sit on in the store for me to try. These are the two cushions I have to choose from. the representative at Ralph Lauren is saying that the Luxury foam fusion is the most firm and the Springdown is 2nd most firm. Please anyone give me advice on what you would pick. I am attaching the discription of both cushions. Please help me decided what to get.

I would like something very firm, this couch needs to last us a while, and it is our main couch, so lots of people will be sitting on it, I am looking for most firm couch. However, wouldn't an all foam couch be not so firm and a spiring couch be more firm. Anyway please see attached photos for description.