We (me+husband+4month old baby) had a great time in this place, particularly due to Ana's good care. Before arrival we had perfect communication about time, pick-up (airport transfer can be arranged, including baby seat in car!), she responded quickly, thoroughly and kindly.
When we arrived our transfer was waiting for us and took us to the apartment really in downtown Lisbon, a perfect little street amidst the bubbly and happening city centre, but in a quiet street with few noises and no disturbance at all. Ana was waiting for us there and showed us everything in the apartment, and a map and folder with all sorts of activities, tips, nice restaurants et cetera. This was amazing and we particularly used the references for breakfast and dinner in the area, so that we could go for dinner downstairs in the same street with the babyfoon, while the baby was sleeping upstair only 30 seconds away in case of trouble: this was perfect! ALso, she recommended lots of places frequented by locals instead of tourists, this was really nice. Major sightseeing and scenery places only 5 minutes of walk away.
The apartment was clean, supernice, spacious and with lots of amenities and toys for the baby. Also, airco in every room was a big plus.
There is no to little noise in the apartment (if you open the windows you can hear nice soft music or street noise from, you know, just being in a city, which we loved. But if you close them, you won't hear a thing). The only thing you might here is sometimes people walking in the apartment above you, as the floors are wooden. But this is not loud or disturbing at all. Great shower in the apartment too by the way.
For a baby, this apartment is absolutely perfect because in a few feet you can see and discover amazing things in Lisbon, you don't need to go far or take a subway first.
Really the only thing that you should consider as less ideal is the fact that the apartment is on the third floor. The staircase is nice though, well lit and firm, but of course a bit narrow for strollers. So I would advise anyway to bring a baby carrier instead of a buggy/stroller/bugaboo. We did bring ours but we didn't use it, mostly because Lisbon is totally unsuitable for strollers due to its many steps, small corridors and uneven walkways. But, this is part of the city's charm and walking around with baby in the baby carrier was amazing, our little one couldn't stop looking at everything he saw. So if you truly want to discover Lisbon, take the baby carrier and book this apartment!