We really enjoyed our stay at Silvana's appartement. It was very clean, there is everything you need and even more. The rooms are big and there is plenty of space for a big group. The appartement is 30minutes away from the center but only 6min with Ubers (which are very cheap there), you'll also find many bus stations in the area. There is a little market in front of the appartement. Silvana is very available and answers very fast when you need information. We really recommend this facility if you want to visit Porto !