Located up and around the corner from very touristy sites, the flat is relatively quiet at night and almost feels away from it all. The rooms face out to the river and cathedral, whose lights are a bit bright for only sheer curtains in the bedroom. Eye mask recommended. The terrace from the bedroom allows you to take in the sights and sounds of neighbors, concerts at the river, and folks walking down the street calling to each other at random hours. The roof does slant down towards the head of the bed, but it's not too bad unless you're taller than 5'9".
The streets are all hilly and cobblestone-paved, so be ready for that. The stairs leading to the flat from the shared entrance and up to the bedroom could be a little steep for some, but seemed pretty European-standard.
There are cats that live in the alley (and all over the city), there is some graffiti, and there might be colorful characters hanging about, but none of these create a dangerous or risky situation as long as you're paying attention to where you're stepping and aren't being careless with your belongings. City living, if you ask me.
The flat itself is quirky in its decorations and layout, and absolutely enjoyable. The bathroom is on the main floor, and your bedroom is upstairs. Double bed was in pretty good shape, and bedding was clean. The couch is cozy for two sitting side by side, and the nesting coffee tables are almost useful, but not quite convenient for eating on. The kitchen is adequately stocked, if a little hodge-podge, and didn't seem quite as clean as I would have preferred, but it wasn't messy or dirty, per se. Plenty of hot water for two people to shower, dependable wifi.
The little bit of complimentary port in the decanter definitely makes you want to set up your tasting at one of the local Port houses, and a small tasting at Portologia would give you a crash course before you chase the single labels. There are also additional bottles of wine available to purchase in Filipa's flat for your convenience, so once you get to your spot, it might be hard to leave again. The cafe where you pick up your key is pleasant, if small. Vinho Verde flows easily, and the light tapas sandwiches are tasty enough to get your exploration of Porto started.