It saddens me to not be able to honestly rate this place 5 stars. I really want to: Martha is lovely, and we were 2 people staying there, it was comfortable with more than enough space. The kitchen is ACTUALLY well-equipped, decent knives, a good working oven, 4 hot plates, a big fridge etc. Even though insulation in Portuguese houses is probably not designed to keep out the cold (vs, say, a Swedish house) Martha recently installed air conditioning units which work as heaters too, and there is an extra one that plugs in which works well.
The only gripe I have of my stay there is the noise. I'm not sure if it's the sound insulation of the window frames, walls etc or the selfish drunk people are just exceptionally loud, or that the apartment is so centrally located that it's 2 blocks away from the bar/party streets. Probably a combination of all 3, either way it was frustrating to be woken up 6 nights out of 7 due to this (and this is after we bought the best earplugs we could find) and then get woken up at 8am by the construction on the main road very nearby.
We stayed here for a month and a half, and besides the aforementioned, it would've been a perfect base for that amount of time. I can't overstate how helpful Martha was, and if she could've magicked away the noise I'm sure she would've.