We stayed there on March 31st and had a similar experience to OP-
What a nice surprise for an airport hotel !
We always try to schedule our flight back to the US for noon or later to avoid a hectic departure on the last day of our trip but Air France called us a few months before our vacation and told us our flight had been cancelled and they had moved us to a KLM flight. Now we had to check in at 5:30 AM.
If the Sheraton Amsterdam hadn't been such a pleasant experience it might have put a damper on our trip-- but the hotel was so accomodating, comfortable and convenient it took the pain out of our early am departure.
When we checked in we were greeted by a friendly agent who told us we had been upgraded to a suite. Our room was spacious and comfortable (I think it's the same room in OP's photos) We grabbed a snack in the (well stocked) club room and were able to have a relaxing evening, knowing we didn't have to worry about getting to the airport in the morning.
At 5:10, as planned, a bellman knocked on our door with a luggage cart and guided us to the KLM check-in-- a short 10 minute walk.
A few minutes later we were reading the paper and drinking coffee in the KLM lounge, amazed at how easy our morning had been.
We've stayed at airport hotels before, but none have been as nice as the Sheraton at Schiphol.