It is an awesome option for staying in Baixa - 5 minute walk from Baixa-Chiado stop (convenient if you are taking subway from airport). Right in the middle of everything - but noise/light level is really low, we were never bothered (stayed in November, so can't say much about peak season).
Apartment was perfect for our needs - really clean and spacious. Hugo is responding very promptly, which made remote check-in and the rest of stay very smooth. Would be very happy to return.