Honestly, I don't find the beds at WDW all that comfortable. They're not terrible, but they're not comfy, either. I always thought that was deliberate so that you get out of bed and get to the parks where you ought to be (spending money).
The Swan and Dolphin feature the Westin Heavenly Beds. I've never stayed at either one, but I have slept in a heavenly bed and it was, well, heavenly.