I stayed in Nelson's apartment with my wife and two young girls for five days. The arrival was easy, as we only had to present ourselves the reception within the apartment building to be given our keys. The apartment was exactly as listened with clean, fresh linen on the beds, and clean towels for both house and beach. In fact, the whole place was very tidy. All the rooms felt very spacious, especially good for children, plenty of storage too. There was everything we needed in the kitchen, having a washing machine was really useful. Swimming pool area was very clean and we used it every day, great for the girls. Lovely view from the balcony of Cristo Redentor. People at reception very helpful and friendly every time we met them, there is also a security guard on the outside gate at night. Also met the neighbour, very friendly. We enjoyed staying somewhere we met Brazilian people and did not feel like tourists.
Apartment was only two minutes walk from a really good, well-stocked supermarket. There were also a number of local bars, cafes, and places to eat just around the corner (never noisy, the apartment was nice and quiet). Ten minute walk to Leblon beach, a beach with a nice family feel, although water quite rough when we were there so no swimming for girls. Leblon neighbourhood much quieter than Copa, streets leafier, less hustle and bustle, less traffic, we loved it.
Bus to/from the airport dropped us on beachfront at the exact street we needed to walk up, an easy walk from there with suitcases to the apartment. There were local buses from very nearer the apartment that took us straight to Cristo Redentor (train station), Sugar Loaf, the bike/pedalo hire shop on the Lake. And to lots of other places I'm sure.
Although we never met Nelson, he answered all our communications politely and promptly. I am very grateful to him for such a lovely stay.