The location of the apartment is perfect, you can walk to every interest point in about 15-30 min max. The neighbourhood is quiet and really pretty, there's everything near.
Sofia is really accommodating for the check-in / check-out and gives you a lot of advices for good places to eat. The apartment have everything you need, the bed is comfortable and the bay window is such a plus. It's very agreable to take a coffee on the terrace on the morning, or to sunbathe during the day. There's A/C on the apartment so when it's too hot outside you can come inside and refresh yourself. For those who are afraid of the cathedral in front, rest assured that the bells are ringing only around 8pm, so you won't be woke up early.
Our stay was lovely and the only disappointment we had is that we had to leave :)