I stayed at 4 different apartments during my trip to Spain and Portugal, and Maria's apartment was the far best!!! It is VERY clean (everything looks new) and I actually think the apartment looks better than it does in the photos. The location is great, you can pretty much walk everywhere and the metro is pretty close too.
As for Maria, needless to say, she was very sweet and friendly. We arrived in Porto earlier than our check in time but she was nice enough to hold onto our luggage and welcomed us to stay at the apartment while they were finishing up cleaning. She would reply within minutes when I had questions and she even left a bottle of wine and eggtarts in the apartment as a welcome gift.
I tried out the bakery (can't remember the name) and reitoria (restaurant) Maria recommended and it was amazing!
I strongly recommend her apartment if you're planning to stay in Porto. I'll definitely go back to her apartment when I'm back there! Thank you, Maria!!