We had an amazing time at Walter's place, it close to the center (approximately 25 mins walk) and various public transport stations that will give you an easy time exploring the touristic sights and the authentic city. The main station is just 18 minutes walking distance away. The apartment was really pretty and small. Walter doesn't lie by saying it's 36 squaremeters big, which wasn't a huge problem for my friend and I, for we are both 'normal sized' (164 cm and 178 cm tall). The kitchen has two cooking stoves, storage with pans and other cooking utensils and a refrigerator/freezer, so that works just fine for fast snacks. The bathroom is small and fits one and there is no real door, hence you hear every noise outside of it, which didn't bother us though. The apartment is easily accessible and the first door after the main entrance. We didn't see a lot of the neighbors, we just heard them at times with loud food steps and playful screams, but those were rather an exception.
Walter himself was always quick to reply and gave us check in instructions days in advance. He was really friendly and caring, making him a great host!
If you're looking for a nice gateway close to the center, we can definitely recommend it! Yet it is probably not the ideal place for taking showers together or cooking excessively.