We spent a month at Francisca's place and it was overally a pleasurable stay. Francisca was friendly, responsive and extremely accommodating to all our needs and requests - e.g. there were issues with internet and a doorknob, and she managed to have both fixed within 24 hours. On the negative side, the place was not fully cleaned up upon our arrival, and there were visible traces of mold (the apartment gets quite wet, at least in the autumn when there's plenty of rain). Other than that, we found Boavista studio to be conveniently located (halfway between city centre and the ocean, and close to a very quiet residential part of the city with lovely parks etc.) and safe, and would definitely recommend it to anyone spending more than a night or two in Porto.