I had the most wonderful time at Carla's place. The apartment is as beautiful as it is in the pictures - my seven year old son loved the little attic space in particular. You'll find everything you need in the apartment; it's very well kept and clean. The location in the historic center couldn't be better if you want to get a real feeling of Porto. You can walk just about everywhere and there are cafés, a bakery and a little shop near by.
Last not least, Carla is a great host - very warm, helpful and welcoming!