We stayed at Radharc Banbha for three nights and it is such a lovely place. The location is amazing, you can't get any further north! The view of the sea is stunning and if you're lucky enough to get sunny weather it's even better. The house itself is well designed, with a large open plan kitchen/living room, which is well stocked with everything you could want.
There were a few downsides however. There are no towels provided so you will need to bring your own, if not, there is an extra charge. There is also a charge to use the WiFi, which is frustratingly slow most of the time. The shower is also quite low on pressure and unsatisfying to use.
Overall it was a good place to see the views and explore the Inishowen Peninsula, but with a few improvements it can become spectacular.