My family and I (including a 9 year-old kid) enjoyed our stay immensely. The flat is comfortable, clean and in an excellent location - literally around the corner from a supermarket, pharmacy, subway and tramway! - which was a huge boon for a short vacation. The rooms are large and comfortable, and our hosts were responsive and accommodating.
If there's any criticism to offer here it's that the (adult) bed was a little too soft for our comfort - certainly a preference thing - and that the flat is clearly built for European-sized people, so my relatively short partner had to climb stools more often than we're used to, but this is very much nitpicking - we loved our stay!