Frank's apartment has a great location if you want to do sightseeing.
however, the communication with Frank was terrible - I had to ask 2 times just to get the check-in information. After asking him for it, he said that he will provide the check-in information at 13:00, but at 14:40 we still didn't hear anything from him (15:00 was check-in), even though I again asked how we can get access to the apartment.
When we then finally had the information, we had to discover that there was no internet (even though it should have been). I wrote Frank and somehow he could fix it. 2 days after that the internet was gone for good and didn't return. So if you are dependent on it, don't rely on having wifi.
The apartment itself is very old fashioned meaning that a lot of things especially in the kitchen don't work and the light switches are far from working properly. the fridge has a hole in it and the stove looks frightening.
there is no light on the ceiling just 2 night lamps.
All in all we can say that this apartment is not great for a stay longer than 1 night but th view was nice. you have to decide if the location is worth all the above-mentioned things.