Opo is a great place to stay - right along the Rua des Flores and in the middle of the thick of things. The location is fantastic with many yummy places to eat and grab a glass of wine within a 5-minute walking distance, as well as plenty of public transportation options (though the city is quite walkable). The backyard is so charming - make sure to enjoy a cup of coffee or glass of wine there during your stay.
The space is clean, comfortable, and perfect for a solo traveler or a couple. Sound definitely travels so make sure you bring earplugs & a sleeping mask as this is a lively street and an active building. I had both and slept well. Would definitely stay here again in the future!