We are a couple with a toddler, and stayed a couple of day in Maria Cristina's apartment, and it's was great.
Large private terrace with amazing view of Porto (including river), perfect location, yet quiet.
The apartment is very well equipped, and wifi works perfectly.
A baby bed and sheets were prepared upon request.
Communication was always easy, and check in was very smooth.
Nothing negative to mention.
I definitely recommend and hope to go back one day.