Hi nanchit,
Welcome to the Mattress Forum! 
I’m glad you’ve found a mattress that feels comfortable to you, but you can’t feel quality or durability when testing out a mattress in a showroom. That can only be determined by the componentry used within the mattress, and unfortunately you haven’t provided any detail regarding this.
When researching a new mattress, the specifications you need to know are listed in this article. If you are able to find out that information about the particular model you tested, feel free to post it back here and I’ll be happy to provide further comments for you. There’s more detailed information about choosing a mattress in the mattress shopping tutorial here.
You can read a little more about Paramount Sleep in post #2 here and the posts it links to. Unfortunately Paramount Sleep doesn’t normally disclose all the information you would need to know to make sure that there are no lower quality materials or weak links in their mattresses, but hopefully with the model you’re considering they’ll be a bit more transparent with the latex used within the product. A forum search on Paramount (you can just click this) will also bring up more general information and feedback about them.
Phoenix