I am past my hostel days and as a 40 something year old I don't do hostels any more. However, all the hotels were booked in Dublin due to Dublin Gay Pride. Gardiner was my only choice. Here is what I think:
I am very pleased with my stay. The staff was very friendly. The bathrooms and toilets were clean. I also like it as it is converted from a chapel and it is a very nice experience. The only downfall was breakfast. It could be arranged little bit better and maybe they could offer a little more than cereals and peanut butter and jam.
I strongly recommended it to the bacpackers and hostel adventurers ;)