We stayed in a few "castles" on our trip to Ireland and most of them are "castle hotels" where the entrance feels like a castle but not too much else. This was authentic through and through. Obviously, they updated some plumbing with bathrooms and such but you are staying in a place that is steeped in history and even open for tours.
There is a wonderful tea cafe on the grounds and its a short stroll into the village to visit the pub (no meals served) or a restaurant of renowned that often needs reservations. A number of other restaurants are within a 10-minute drive.
The whole Fellowship of Isis connection was absolutely fascinating. They share about it on the tour.
Be sure to allow enough time to stroll through the gardens and grounds.
Good chance you'll meet the owners of the castle who live on site and are very kind, helpful, and down to earth.