I chose this hotel based on the car park and for this reason Hotel Grebel is good. A private car park that is secured via a roll up shutter at night, which has a push button to electronically open it if you need to exit.
The staff are nice, but limited on English if you are unable to converse in German. There are two flights of stairs up to the room, but no lift, so someone who needs assistance may choose elsewhere. Cosy room with vintage style wardrobe, plenty of space for shirts and shelving for clothes/shoes. Sofa, TV and desk/chair in room, but no bin for rubbish nor cup for water. No bother to me as I used the commercial bin in the car park and had bottled water with me.
Bathroom was well stocked and shower worked well. Towels were replaced daily and bed remade. Couple of holes in the wall here and there, but clean enough.
Biggest problem with my room was a loud annoying whine like a boiler/generator coming through the wall from next door, which I'm sure was a different building to the hotel. Despite this I slept well as the shutters on the window making the room pitch black and reduce outside noises.
The hotel restaurant was closed on the Friday when I arrived, but was packed with locals and guests on the Saturday and Sunday. The locals also make use of the car park, so if you come back late with a vehicle you may have to squeeze in at the back. Additionally I could not get the WIFI to work.
I would use this Hotel again, but a different room.