We absolutely loved our stay at Marcos house in Porto. The house has about 7 flats, with a nice small garden with a river view. The flat was extremely modern and clean and has everything one needs. It is definitely big enough for two people and we especially loved the cosy beds. It looks exactly like on the pictures and we felt at home right from the beginning. It is a quiet area, but still you are at the river in 2 minutes and also have a big supermarket near by and if you don't like to walk there is a bus stop very close too.
The communication with Marcos was good, also during our stay. Marcos explained how to get to the flat very detailed, which made it easy to find for us, as this was our first stay in Porto. Marcos also gave some excellent tips for our stay and he ordered us a taxi for our leave which was very helpful and kind (as the flat can be a little hard to find). Marcos also speaks English and German very well (as everything is on portuguese on this side, we were unsure at the beginning :)).
I would highly recommend Marcos and this flat and would love to come back.