We stayed 5 nights at Luis' flat. Luis a pleasant host, as is his wife who welcomed us. The flat is well equiped. The location is great, very close to the centre but still in a quiet area. We walked everywhere in the old city. We enjoyed the balcony and the view (on the Douro and the Dom Luis I bridge). We also appreciated Luis coming by on the eve of our departure.
All in all, I have no hesitation in recommanding Luis' flat.