I stayed here with three friends, and our stay at Martas place was great. Good size apartment, nice and tidy. Martas husband welcomed us when we arrived, gave us some tips about what to do, and even left us a bottle of wine!
If I had to be picky, I would say that the backyard didn't get as much sunlight as in the pictures, probably because some plants/trees around the garden was blocking it.
Other than that, our stay was pretty much perfect, and definetly worth it. I would highly recommend staying here for a trip to Lisbon. :)