The apartment is mostly fine if you are not looking at details. The area around is great with nice small park and a lot of good restaurants and pastry shops. It is also not far from the tourist attractions.
Unfortunately the apartment has many minor flaws. I have tried to discuss some problems with the owner at the beginning of my stay, but he was unwilling to help. The big one for me was the Internet connection, which I've asked specifically before making a reservation, because I needed to work for a few days. The owner assured me the Internet connection is fast, but I've found that it was much slower then promised and (which is much worst) it was very unstable. I've reported it to the owner, but he didn't want to help with that.
I think the apartment needs serious renovation. Mold is visible near the kitchen window and in the bathroom. Paint is peeling off some walls. There are huge holes around some power sockets. It is not safe if you are going with children and it looks pretty bad. There are holes between some floor panels.
I am a bit worried about the cleanliness of the apartment. I've found a lot of mold inside a washing machine on the door boot seal. There was a dust here and there and some shoe print is visible on the wall.
I was living alone in the apartment so it was mostly fine, but the amount of the plates and kitchen utensils is definitely not sufficient if you are going with family and you plan to cook (even occasionally).
All in all, it is not a very bad place to stay, but it has a lot of minor flaws which will probably not ruin your stay, but definitely make it much less attractive.