We spent three days in Dublin and we're so happy we chose to stay at John's place!
First of all, the location is excellent - despite being a couple km from the city center, the bus that takes you there stops literally outside the door, so you'll easily be able to get there in 15 minutes. That's also the same bus that comes and goes from the airport, which is extremely convenient if you're traveling with luggage.
Even though the decor is a bit spartan, the apartment in general is clean and comfy and has all you need.
John was an excellent host - kind and friendly since we first contacted him, he proved to be just that when we met him, and was happy to give us helpful advice and clear indications to go around the city - he even lent us a public transport card which gives you a discount on every ticket!
I absolutely loved my time in Dublin and I would definitely recommend staying at John's place!