We stayed at Esther & Gemma's apartment for the 2015 New Year. The apartment is located very conveniently (a metro station is just across a street); just a 10-minute walk from Sagrada Familia - but it is also very quiet so there was no problem getting good sleep and rest at night.
The apartment was clean and neat and had all the necesary amenities for a comfortable stay. The description and the photos provided here are precise and give a very accurate impression of what is to expect from the apartment. So, if you like the picutres you will like the apartment itself.
We would also like to say a special thanks to Gemma who was our primary contact and hostess. She was very helpful and flexible and permitted us to drop in our luggage earlier than the check-in time (we could not properly check in as the apartment was being cleaned) and to leave our luggage for a couple of hours after the check-out so we could use the most of our time in Barcelona.
In all, the Pink House is definitely a recommended place to stay.