Since we fulltime on our Pinnacle we have been looking at replacing our factory mattress with something that sleeps better.
We looked at several styles including Sleep Number, Euro Top and Memory Foam mattresses, finally we ordered a custom made Memory Foam mattress with the Gel Infused Foam in the top layer to sleep cooler.
The mattress company I was dealing with said, do not measure the current RV mattress, measure the platform base in the RV that it sits on.
I measured the exact size of our Pinnacle King Bed's platform including the corner notches (the factory mattress never fit very good, overhung the sides and the end a little and overhung the notched corners on the base to the point you could not sit on the sides or corners to put on socks and such).
Also when closing the bedroom slide the factory mattress always would scrunch up due to its length.
Now our new mattress is well made, fits perfect and sleeps great.
Since it is the same size as the platform I can sit on the side or corner of the bed and put on my socks in the morning.
The first night with the new mattress I did something I have not done in a long time, I overslept the next morning.