Marta was a great host! She worked with us on our check-in once we had our flight itinerary so we could at least drop our bags off and get around the city. After we were settled in, things went smoothly but she was available for any questions that arose.
The flat itself was a really great spot for us as "home base" for our two week stay. It was easily walkable to Praca do Principe Real and not far to Barrio Alto, but a little out of the way so it wasn't too loud or busy. We were able to walk to almost every attraction we wanted to visit from this location.
(as a side note, if you need anything from a farmacia, go to the one at the bottom of rua da imprensa nacional - the owner is so nice and helpful!)
The only tip I would give to average US citizens like me- the oven settings are very different from ours, so it was a bit of a learning curve. I would ask for instructions if you plan to use it so you don't burn food like I did- ha ha