We experienced the Cordosas Story Red appartement as a comfortable place to stay: modern furnished, a good an quiet airco, very spacious including a kitchen larger than ours at home :-) and located right in the old center of Porto. Check-in was clear, with a key case with a number lock. And check-out equally easy.
On check-out we forgot to take a bottle of ours from the fridge. The Porto City Hosts promptly helped us via their WhatsApp chat, showing a photo of the bottle to check if that was the missing one.
In all, the appartement is a nice place to stay for several days discovering Porto. Very much recommended!