40 eur/night is a fair price for this flat comparing to available alternatives. I would come back in that case.
+ generally clean apartment (some minor detail)
+ clean toilet
+ good location (bars, cafes etc)
+ good (hard) bed
+ quiet
- decoration remembers Vaclav Havel.
- place needs urgent refreshment (painting and resecoration)
- do not look at the floor
- window curtains are very thin (light).