We stayed at Millbank for 5 days (family holiday including a baby). We had a very warm welcome and Pauric and Kate were fully accommodating as to our requests. As others have said, it's very large and imposing — much more impressive than the photos show.
You can spread out across the various living rooms and have quiet time away from each other when needed! The bedrooms have comfy beds and shutters to make it fully dark.
We didn't use the cottage in the end as everyone wanted to be in the main house.
It's not freshly decorated or contemporary, but that's in-keeping with its history, and overall it's tastefully done with nice touches and original portraits etc.
The pool got loads of use and we also liked the sauna and hot shower by the pool.
The gardens/woods are lovely to walk in and, even after this incredibly hot/dry weather, we still had a babbling stream to see on the edge of the property.
It took a lot of googling to find the best places to eat & drink, as we discovered that pub lunches/gastro pubs are not the norm, other than in bigger towns. Our favourite place to eat nearby in the evening was Lily's bar & kitchen in Portlaois. It's worth driving to Kilkenny as it's beautiful and there's the castle and fab pubs/restaurants - Langtons was excellent.
Nature: Kinnitty forest is stunning - we did the 'fairy walk' in the grounds of the castle hotel.