VERY cool apartment right on the Liffy in Temple Bar near the Ha'Penny Bridge: spacious with a great bedroom, bathroom, and kitchen. There's a very busy bus stop outside the door, but just say excuse me and people happily move. Be prepared for stairs (as mentioned), but know that they are wide and even with a good handrail.
We LOVED the rooftop area and had wine up there are on two beautiful nights. The access stairs are just a continuation of the main stairwell (good stairs), and we did not mind the maintenence materials piled neatly along one side of the stairs. There is a washer INSIDE the apartment, and the dryer is just ourside the apartment door in the upper stairway - both free for your use.
The locks were strange on the main access door, but the nice owner of the Mexican resto next door helped us out.
The one draw back to this apartment in the summer is that it was a bit hot with no fan provided (hopefully she will add a fan soon). We would have happily left the windows open but there was noise until 2am from the folks in the back alley. Our solution was to leave windows open all day to keep the air flowing so hopefully at night it wasn't so hot (only one night was badly hot).