The flat is excellent - this was our first time travelling with a baby so we spent more time in the apartment than we would usually and it was very comfortable and had everything we needed. The possibility of hiring the baby-cot was also very useful.
The neighbourhood is very pleasant and connects with central Porto easily and quickly via Metro.
Communication with Sara was excellent during the book-in process. Check-in was handled by Sara's husband Hugo, who was extremely friendly and helpful: he also arranged transport to the airport for us and even brought our luggage from the apartment before picking us up from elsewhere in Porto.
All in all highly recommended.