Hi lifeincolor.
Welcome to our Mattress Forum. 
Sorry to hear you’re having a too-firm sleeping experience. Unfortunately, I wouldn’t be able to tell you which of their current models is most similar to your 2007 without knowing the specifications of that mattress.
Which model do you currently have? Are you definitely looking to exchange?
The “good” thing about a too-firm mattress is that you can soften your experience. There are also some topper guidelines that you can use in post #2 here that may help.
It’s likely that your bed did soften over the years, especially if it contained polyfoam or memory foams. 14 years is a long lifespan for a mattress, and the materials do soften and break down over time.
NikkiTMU