I echo a previous guest's comment that staying in Sarah and Sean's place was like living in a hotel. This room is clean and beautifully designed. The bed is comfortable and the shower has plenty of hot water. Sarah made the check in/out process extremely easy, helped me book a taxi to the airport (15 minutes away), and treated me with breakfast in bed every morning. You can't ask for more!
You might feel hesitant at first to stay a 15-20 minute DART ride away from the touristy, city center, but I found it to be very refreshing. Sarah and Sean's is just a 2-3 minute walk from the Harmonstown train station (from the city center, take the train that ends at "Howth" station). It's located in a quiet neighborhood that allows you to get a different feel for Dublin (and good sleep)!