How important are they? We had a 9" tall box spring that came as part of a set. They made the bed too tall to get into, so I removed the wood frame from the box springs. That corrected to a better height, no longer trying to climb into bed. Now the pillow top mattress 13"-14" is lacking in support, kinda mushy, yet not uncomfortable. What do we need to look for in a new box spring? Is there a difference in quality and support? The set is about 10 years old & is is a queen size bed.