We loved our stay at the Castle Hotel. It occupies several converted Georgian houses, making it L shaped and a bit of a labyrinth inside- a beautiful, magical labyrinth. No danger of getting lost; directions to the rooms are all well marked, and it's great fun. I loved the decor, especially the framed sheet music of old songs. The staff are absolutely delightful and happy to answer any questions you have.
We booked a triple, and were delighted that we were put in a suite with two bathrooms. Lots of space, and a nice view of the church and the park from our windows. Temperature was very pleasant, and beds were very comfortable. Water pressure was so-so, and one of the bathrooms had very slow drains, but as there were two, we didn't mention it since it didn't affect our stay. Plenty of towels, replaced daily. Be patient with the water temperature; it can take a while to warm up (typical for many older hotels). Breakfast is good, with a hot or cold option; you can get a Full Irish breakfast if you want (we did once; it's a lot of food).
The area is very good- short walking distance from main shopping areas, and maybe 10-15 minutes walk to the GPO.
A delightful stay at a delightful, historic hotel. I was so sad to leave and look forward to going back. Highly recommend.