Did this tour yesterday and although being from Dublin I had been to all the locations we stopped at already, the tour was well worth it. Our tour guide, Trevor, was excellent.
He was so knowledgeable on the history of every little town and village we passed through and had great little anecdotes to tell. Not only that, but he told them all with a great dry humour.
Our driver was great too, Jim I think his name was. It was his maiden voyage on this route and he managed to navigate some pretty difficult terrain perfectly.
Unfortunately we had a rainy, grey day, but even then it didn't matter too much.
I only give 4 stars instead of 5 because I would have preferred to stop for food in another town...but that's just a personal thing.