The flat is small but has everything you need to stay overnight. It had some small issues with equipment like kettle or hooks in the bathroom, but I believe it will be easily fixed by the host.
The location is great for travelers - few minutes by walk from the train station, and 15-20 min by walk from the historical center. But as it is close to train station you have to be prepared for the environment - it is a bit noisy, but same as it is in any city near the train station. You have to be prepared that flat is on the 11 floor, and the elevator on some hours will cost you 10cents - it was first time I saw something like this).
To summarize 4 out of 5. Good but not perfect to stay over night. Check in and out is great! Communication is top level. You will have some travel advices, what is great.