I stayed in John and Sinead's place with four friends for two nights over a weekend in September. John and Sinead's place was comfortable, clean, well placed and accurately listed. I would stay there again if the stay was only relating to the apartment. However, once you take into account John and Sinead's willingness to go to the next level to help their guests, I wouldn't hesitate to recommend it to anyone travelling to Dublin. They were supremely helpful and very communicative.
Ranelagh is a great area, with a number of cool bars and restaurants and is well connected with the city centre via public transport or via a 30ish min walk.