The main reason for the mediocre rating is that the water heater broke during the second day of our stay, which resulted in no heat for the apartment (heat is generated by hot water running through the radiators) and us having to take cold showers, supplemented by the hot water we boiled in the kitchen.
The first time we noticed that the water heater was not working, we contacted Doris and worked with her for two hours to troubleshoot the problem until she was able to get a plumber to come by later that evening. She was very responsive. However, the plumber informed us that he was unable to really work with the water heater in fear of invalidating the warranty on the unit. He made his distain for the quality of that brand of water heaters very clear.
He restarted the whole electrical system and was able to get the boiler to reset. However, when I woke up this morning, I found the the issue had reappeared.
While I appreciate Doris's effort in getting a plumber and a partial refund for the second night she sent, I would NOT return to this Airbnb.