Five of us just stayed at Tiago's place. We loved the apartment! It's huge, airy and immaculately kept. Tiago was very accommodating with our late arrival and allowed us to keep luggage until our late flight. His guide to Porto is very comprehensive - I would recommend getting it before you get there!
Getting to the accommodation is easy via taxi or metro. Main sights are a quick metro ride or taxi away.
Thoroughly recommend it!