I had a great stay at Pilars house! It is very beautiful, light and modern. It has been very clean as well. I haven't met Pilar as she has been on holidays herself but I lived there with another very nice young german woman who was a guest as well and regarding to the messages that we've sent each other, Pilar seems to be very nice and kind. :)
The house is "quite far away" from central London but the public traffic network is very good in this area so it is no problem to be in central London very fast!
I can absolutely recommend Pilars place for a stay in London! :)