I had a very pleasant month-long stay.
The apartment is very spacious and has everything you would need for a long stay.
Communication with the host was very smooth and helpful.
Internet speed is awesome :)
The surroundings are quite nice. Supermarkets are not far and there is a park nearby if you like to go on walks.
Some tips:
If you are planning to use public transportation, be sure to research Viva Viagem card usage.
If you are planning to use busses number 2 or 11 (Vimeca/LT Transport provider), for example, you would need a card with tickets on it.
If you are planning to go to Lisbon city center and use yellow busses, metro, or for example take a train to Sintra or Cascais - the previous card would not work for you, you would need another one with "Zapping" money on it (For Carris transport provider). Basically, it depends on transport provider what kind of public transportation paying options are supported via Viva Viagem card.
Some places only accepted Portuguese bank cards (my Revolut visa was not working), so be sure to keep some cash with you.