My partner and I spent five nights in this apartment and had a reasonably good experience. The location is excellent, very central to all Cork has to offer, and a 10-15 walk to the train station and bus terminal. As the listing notes, it is upstairs from a bar (with several others on the street) and on Friday and Saturday nights, it was quite loud until around 4 am.
The flat has a few quirks due to being in a commercial building. All the doors are fire doors and thus slam, and a few lights stay on permanently or are motion-sensored. As others have noted, it is up two flights of stairs, so probably not the right choice for someone with mobility issues.
We used the dishwasher and washing machine successfully. There were some kitchen staples (salt, pepper, and one or two other seasonings) that seem to have been left behind by prior guests. The cookware is a little lacking. There are three small-to-medium pots but no large pot or frying pan. We wound up resupplying the unit with olive oil, so you should be good if you stay there in the next month or so ;)