Me and my boyfriend had an amazing stay at Karen's apartment. It was very clean, newly renovated, lovely decorated and had everything we needed. The location can not be beat! It is close to the central station, the old town square, the Charles Bridge and even the castle is not far, so we were able to walk everywhere.
Still the apartment is in a very quiet area, so no street noises at all.
The communication with Karen was always good. Even though we didn't meet her personally, her colleague, who checked us in, was really nice and even gave us some advice on our trip and what was going on in the city at that time, which was really helpful.
To conclude, I can definitely recommend this apartment and would love to stay there again during my next trip to Prague!