Our party of 6 (3 seniors, 2 adults, 1 child) loved the place. It is very spacious with nice views and great terraces. There are two bakeries next door and at least one of them worked through Christmas holidays. So we could get fresh pastries and bread every morning.
It is fairly close to the center but we mainly took subway anyways. Closest stop is less than 100 yards from the entrance.
It is obviously flat where people live and different from standard hotel room. We loved it because it has so many small touches that make you feel like home.
The only thing to keep in mind is that it is on the top floor and you have to climb 2 floors to get there from (small) elevator. Might be a bit of the challenge for elderly people after long day of sightseeing or bringing your luggage.
Elxe is great host, answered all our questions very promptly, met us personally and shared number of local tips. She even got a nice Christmas tree for us and provided decorations we could use! Our 7 year old loved it.