We had a lovely stay in Porto. The apartment is well positioned - only about a 15 minute walk down to the waterfront, the cathedral and the other major sights. There’s a supermarket about 5 mins away and the metro is close too.
The apartment was clean and well appointed. The only thing to be aware of is that of the 2 upstairs bedrooms, one has a very low ceiling, sloping down almost to the bed, and very little floor space. It is fine for one short person (my daughter is 5’ 4” and loves small spaces so was very happy there!), but there isn’t really enough room for two people (although there is a double bed) or a tall person.