We did have a very short visit at NH Stuttgart airport, like 8 hours. But for this short visit we had time to explore some of the hotel facilities. The check-in was very fast, convenient and with no errors. Room was very nice and very clean and quite big, nice bathrooms. Hotel bar - well the waiter didn't have that much experience of drinks but was very friendly and helpful which compensated.
Checkout at 4.30 in the morning was no problem at all and there was even coffee and croissant at that time ready for us.
Couldn't ask for more.