Isa's flat is priceless if you want to go to Barcelona.
My parents stayed there, and being in Plaza Espana while you're in Barcelona allows you to get to the center (P. Catalana) in 4 stops.
Very nice location and flat corresponds exactly to the description given.
Moreover, Isa is very helpful, whatever you could need, you'll find there, she knows the city and in case of problems you can count on her.
My parents were not even so comfortable speaking english or spanish, but there were no problems at all.
Highly recommended, without hesitations.