Amazing apartment, great view and lovely neighborhood with everything one might need within walking distance. AC worked great in all areas (during our stay temperatures reached about 39 celsius so definitely usefull!). The house is fully equiped, plenty of space, great beds and comfy couch.
Transport service: DO NOT USE THIS! We were very dissapointed to find out the service picked us up late, and dropped us off, NOT at the appartment, but at the LovelyStay offices to do the check in process, get payed and leave us standing there with our luggage...? Either we payed him another 35 euro's or had to catch a taxi or uber. We ended up halting a taxi who took us for a 5 minute drive which cost us less than 5 euro's so be advised. Take a taxi from the airport and have them wait, it will cost you around 15 euro's total minus the dissapointment and hassle.
Area: amazing. Coffee at the gelato store a few doors down was delicious every morning. Kind people. We stayed for a month so we rented a car to really explore the entire area. Sintra, Estoril beach (Tamariz), Costa da Caparica, Belem boulevard etc: worth a visit. Parking is payed (free from 19:00 pm to 9 am and the weekends) so make sure you check that. Supermarkets are a few steps from the house, as well as bakeries, pharmacies and other stores. We did not use public transportation but the tram stop is just around the corner and bus stops in the street as well. Don't forget to use your mask in public areas or you won't be allowed to enter due to COVID-19 regulations.

Upstairs neighbors kept flooding the balcony with dirty water that came trickling down to our balcony which means we could not use it as much as we liked. This should be checked cause it's annoying and dirty.
Other than that, enjoy the area. The appartment is really amazing, clean with amazing views and a calm area (apart from the neighbors running kids in the morning!).