We had a very good stay without any inconveniences in SeeYou's apartment and enjoyed our 5 nights in Lisbon!
The Check-In was perfectly organized: SeeYou explained us how to get to the apartment from the airport (taxi or public transportation) and waited for us with the keys.
You literally live IN Bairro Alto: Such a great experience. Restaurants, bars and several shops not even in "walking distance", you just need to walk out the front door. Metro station "Baixa/Chiado" and tram station "Praça Luís de Camões" reachable in 5 minutes walking.
Depending on the day of the day of the week, it may indeed be very loud at night in the streets nearby. Therefore, this recommendation might maybe be meant more for young people than for families.