Hi maddog,
I’m not sure how long you’ve been sleeping on your mattress but I would keep in mind that there will be an initial break in and adjustment period with any new mattress so I would make sure that you give it a few weeks before exchanging it (see post #3 here and post #2 here)
If you do decide to exchange it then I also hope the Dreamfoam 13" gel memory foam works better for you as well. It would be comparable to the Tempurpedic Cloud Luxe (which is Tempurpedic’s softest mattress) in terms of firmness.
I’m looking forward to your feedback once you’ve either slept on your mattress for a little longer or exchanged it for the new mattress and had the chance to try it out.
Phoenix