I booked this apartment for a long weekend getaway with my sisters. We initially reserved the apartment in Parnell Street, but because my sisters arrived from the US at 6 am in the morning, Hotels.com staff assisted me in contacting the property and arranging an early arrival. They moved us to an apartment in O'Connell street which has an even better location. The access is easier, as the key is inside a locker and they sent us the code. We were able to access the apartment earlier.
It's a small but clean and confortable place. We were on the third floor. For those traveling with heavy luggage or have physical limitations, please be aware that there's no elevator. The apartment is small, so it feels a bit crowded when lots of luggage is placed on the floor. I suggest to the property managers to instal some hooks next to the door to hang coats. It was not ideal to just place winter clothes on the chairs or table. There's also a mirror placed way too high up in the wall. Unless you're a woman over 1.80 m, it's impossible to use the mirror to do any makeup while the bathroom is being used. I hope these suggestions are useful.
Finally, it seems there are several people managing the property, so we didn't get the same information. When I arrived in Dublin, one guy on the phone told me I couldn't check in until after 4 pm (really late!) while a very helpful lady sorted this situation out for us and saved us from walking around Dublin with luggage and jet-lag for 8 hours.