I just replaced my split mattress on my 24J with a Lucid 6". I had to cut the side and corner to fit from a queen size. It's a vast improvement over the stock mattress split right and left and at the mid back.
I also purchased a few more squares of "froli" springs to fill in the hinge areas under the mattress.
For a $150 price range it's well worth the money.
Enjoy Life! It's later than you think. Life changes in a second. There isn't enough time for cheap booze and cheap cigars.