I had the honor of being Andrés first guest, and I can strongly recommend the apartment. I stayed there 2,5 weeks with my dog, and the location was super for us as we could take nice morning walks along Playa do Sul or go down to Foz do Lizandro for a fresh water swim during those hot days. Or even keep on hiking to Sao Juliao beach.
The apartment is located about 15 minutes by foot to the city center with bars and restaurants and about 10 minutes from the big supermarket Continente (my favourite). There is also a mini mercado just up the street on the hill where you can get fresh bread for breakfast every morning. Make sure you have lunch at Sete Praias on Praia do Sul before you leave Ericeira or Drinks at the Tiki Bar!
Practical info - there are a lot of stairs to climb to get to Andrés place, but the stairs are quite well constructed so it doesn't feel so bad. But when you get into your vacation home you have the best view ever THANKS TO those stairs. The sea will overwhelm you. I strongly recommend staying there!