The apartment was very cute and as a 2 bedroom, was a real find! My friend an I stayed for about a week and found it to be quite spacious - with a big enough bathroom, a cozy living room and 2 proper bedrooms. While we did not make use of the crazy Bairro Alto party scene as much, the area is super central - a short walk from Alfama, Praca de Comercio, the Time Out market, Pricipe Real, Chiado etc, and overall extremely convenient.
Yes, you will be in the busier side of Barrio Alto but with the windows shut in the night we slept really well.
Last (but not the least), thank you to Richard for helping me carry my heavy suitcase the 3 flights of stairs and smiling through it all. Richard was very responsive to all my calls on all kinds of queries that we had. Overall 5 stars!