We really enjoyed our stay in Maria's place! My husband and I were there from mid August to mid September - a whole month. For us it was great. We loved the fact it was so bright and airy because of windows on both sides of the building with a good through breeze most days even when it was hot. There is neither aircon nor fans here so I'm guessing that is usually the case in Porto. The living room was cosy and comfortable with enough space for two people to work. The kitchen was really well equipped, with lots of pots/pans etc and even a juicer and stick blender. The decor while a bit old fashioned is really charming - it's so nice to stay somewhere that is not fully kitted out by Ikea for a change!
The walk into downtown Porto is all downhill, Ubers are cheap here and the metro is only about 5 mins walk away. Some fruit/veg shops and a grocery store nearby along with some local cafes for a coffee or simple bite.
All in all a good place to base yourself in Porto.