Rute's apartment is great! It's a small place, but makes very good use of space, with the bed above everything on a mezzanine area. Certainly comfortable enough for 2 people. The steps up to the bed were fine for us - though admittedly anyone with mobility problems would struggle - and the bed itself is very comfortable. The view from the small terrace, to the direction of the river, is lovely, and the terrace gets great sunlight in the afternoon.
The apartment has a perfect location. It's a short walk to the Metro system (Trindade station), so really easy to get to from the airport; a 5 min walk to a supermarket; a 10-20 min walk to all the main sites of the city; and <10 mins from lots of good restaurants and bars.
Communication with Rute was good, even though unforeseen circumstances meant she3 could not meet us at the apartment. The key collection, check-in and check-out were still absolutely fine. The bottle of local wine on arrival was a nice welcome after a few hours of travelling!
The only negative point to our stay was that, being on the top floor, we had a little trouble with early morning noise from seagulls on the roof a couple of times. If you're a light sleeper, I'd recommend taking some ear plugs just in case; or having that extra bottle of Douro wine before bed to knock you out!
That's only a minor point though -- Rute's apartment is a lovely place to stay for 2, in a great location and good value for money. I would highly recommend Rute's apartment for a visit to Porto!