The Estoril (-----------------------) was only EURO 28 per night - and we reminded ourselves of that during our Feb 05 stay. It's in an older building above a shop in a (supposedly) pedestrianised shopping strip. There are only stairs - we had to lug our bags up two big flights.
Former (presumably larger) rooms/apartments have been divided into strange shapes in the current pension. Ours was a reversed "L", with our double bed at the foot and a single bed in the stalk, with the only window at the end. It was clean but the furniture was pretty basic. The bathroom was in the corner and clean, but small and also basic - a rectangle surrounded by a partition.
Because the (new) walls are not all that solid, we had cigarette smoke wafting into our room during the night. Also, our TV didn't work. Although breakfast was officially available, the hostess didn't seem interested in providing it and encouraged us to use the cafe next door. Otherwise she was friendly enough, but not particularly helpful. The location was good - just outside the centre of town - a 10/15 minute walk to Sao Bento station, for instance.
The Estoril is recommended in a number of guidebooks and, frankly, I was surprised. Maybe it compares well to other accommodation in Porto - everything's relative. It was clean, seemingly safe and cheap - and for three nights that was OK for us.
This review is the subjective opinion of a TripAdvisor member and not of TripAdvisor LLC