I had a thoroughly enjoyable time while exploring Lisbon and staying at Ingrid's.
Ingrid's place is quite close to Lisbon's main avenue, the underground rail, downtown tourist areas, and best nightlife areas, close enough to get their in 5 minutes on foot (perhaps 10 minutes to Figueira square) but far enough away to not have to worry about noise all night, crime, or paying ridiculous tourist prices nearby.
I thought Ingrid's flat was quite charming. In my opinion you're not doing the tourist thing in Portugal correctly if you don't stay somewhere where there are azulejos (the tiles with geometric motifs that are typical for Portugal) inside the building (as is the case in Ingrid's living room,) or outside. It would be like touring Switzerland and never eating cheese or chocolate.
Ingrid herself is an exceptionally warm and pleasant person, and I suspect it would take an enormous effort on your part to not get along with her and thoroughly enjoy your time.