Seriously forget this mattress

We have this mattress at home and it is great but then we bought one for our cottage and it is not the same. It is way too soft, much softer than the mattress at home. It is supposed to be the same mattress! Same size and everything! We bought a third for our daughter's room, it is really hard compared to the other two. Obviously Simmons company is not using the same materials for each mattress. I had even heard from the company I purchased the mattress for that once in awhile they put the wrong tag on a mattress. For instance putting the firm tag on the soft mattress or vice versa. I am so frustrated to have finally found a mattress we liked, buy 2 more and they are nothing alike!