We have a 2017 White Hawk 28DSBH with the new Sealy. Have slept on it twice so far, but with a memory foam topper right out of the gate. On top of that we then added a pillow top queen mattress cover because the setup was a tad too firm without it. Everyone's ideal mattress feel is different, but for us it seems pretty dialed in now, very much like a decent residential mattress. Slept very well on it.
Oh, and as others have commented, the Sealy is a pretty tall mattress...
2017 White Hawk 28DSBH, Glacier package
2010 F150 XLT SCREW, 4x4, 5.4L Triton, HD Tow
Andersen No-Sway Weight Distribution Hitch
Our White Hawk photo album