We have a 4 year old plush top hybrid mattress. On a firmness scale of 1-10, where 10 is the firmest, our mattress was a 4. According to Wayfair, this ComforPedic mattress is a 9. 
     The difference this mattress has made for us cannot be overstated. It is firm, but still has enough softness to be springy. Certainly sitting on it is much more comfortable than sitting on a softer mattress,  much better for our backs.     
     I sleep on my side  stomach primarily. I was waking up with hip and lower back pain with our old mattress, but after a week of sleeping on this ComforPedic, it is almost gone. I wake up in a much better mood with much less joint discomfort.
      We’d previously tried out the Casper  Novosbed mattresses  found them to be too hard and uncompromising. This is perfect!!!