In the „old” business class seat you will get thicker padding and in “The Room” you will get white sheet. It is because the seat in “The Room” is wider and the padding from the other seat won’t fit. “The Room” bed is in the L shape.
Personally I think that the padding is more comfortable than the white sheet which is simply too thin.
I brought that into attention of the crew on my first flight in “The Room” and the response was that they are working on improvements.
Just ask for another one if you need it. It is not a dealbreaker, you will still get a decent sleep in both.