Hi mojowomyn,
You can see the details of the 9500 in post #2 here.
The Octaspring website here also has more details about the differences between the different models. The differences are primarily in the type and number of the Octaspring layers (some are polyfoam and some are memory foam).
ADMIN NOTE:Removed 404 page link | Archived Footprint: octaspring.com/memory-spring-mattress/
If you find out more specific details then it would be great to post them here.
Phoenix