Micheal was very welcoming and helpful. He was nice enough to wait for us until past midnight for check-in.
The flat is exactly as described. It is comfortable and well-located, very close to the tram and only a 10-minute walk away from the historical centre of Dublin. Smithfield itself seemed to be a pleasant neigbourhood, with good pubs and cafés.
I would really recommend staying at Micheal's flat if you want to discover Dublin.