One word word will sum up our stay at Casa Nossa - HOME! We really enjoyed the stay - and felt we were an avg member of the neighbourhood. There are many amazing restaurants serving authentic Portuguese cuisine in a non-glamorous setting within 0.5 to 3 mins walk! You pay local prices by being a local! There are small groceries and cafes and anything else you can imagine. We walked to the center in 10 mins or less every time we went there. Metro is a 5 mins walk away. You can catch buses there to visit Belem with just one stop in between, or catch the Blue line to go just about anywhere. Though Clara has a great kitchen setup we ended up eating our or bringing food to the house.
The one thing that was tricky for us was finding the light switch in the stairs, so make sure you ask for its location. Also, we had a stroller/pushchair which we had to bring upstairs every time we went out - we didn't mind that at all - thats a small price you pay for staying at an amazing apartment hosted by an even more amazing host.
You will love Lisbon - we could have easily stayed here a month, and hope to be back to Clara's apartment in future.