The flat is extremely spacious. We were 4 adults and a toddler and didn't feel crowded. I was visiting family and they ended up coming to the flat and it was very comfortable to have them over for some mate (Argentinean tea) and pastries. Having 2 toilettes helped a lot.
Since I travelled with my toddler having a washing machine was invaluable. And they even provided some washing soap so we didn't have to buy which is really good since we didn't stay enough to use a whole package.
The balcony has security for toddlers or babies. I wouldn't recommend it for children over 2 years old (those already climbing) as the security is not all the way to the sealing of the balcony.
Communication was very easy and I was allowed to check in very early in the morning and check out also very early since my flight was early.
Would come back again! very nice flat overall!!