The apartment in Porto was everything we had hoped for, and communication with the hosts was easy and quick. Location was great with Sao Bento station and the Cathedral and top level of the bridge minutes away.
As mentioned in other reviews, groups of drug users congregated across the entry to the flat, but at no stage did they seem in any way rowdy or threatening. It is to be expected in any larger European city in downtown/ railway station locations.
Despite the above, we would happily return and recommend to our friends.