We had a wonderful stay in Osvaldo and Susete's apartment! The apartment is modern, very clean and comfortable, and we adored the windows and balconies overlooking the Rua das Flores (and the sound-proofing shutters truly work! Very little street noise, especially with the fan going). Susete and Osvaldo were very conscientious communicators which was greatly appreciated -- clear and easy instructions for accessing the apartment and gave us some great recommendations for restaurants! Location is really amazing -- right next to Sao Bento train station (very easy arrival with all our bags) and in the middle of all the main sites. We walked everywhere and were in love with Porto by the end!
The only head's up for travelers we'd note is that the room does get quite warm -- we were there in August, so not surprising! There is a fancy Dyson fan that does a nice job of cooling things off, but there isn't a central air unit -- we were personally very comfortable, but wanted to note for travelers for whom colder temperatures are important for getting a good night's sleep.
Overall a wonderful stay and we would definitely rebook if we find ourselves in Porto again (which we hope we will)! Thank you to Susete and Osvaldo!