This TV series is very captivating. I find it to be like an Irish version of Sons of Anarchy that aired and was was popular in the US.
However, there is less graphic gore than S.O.A. but the same great character development. It's a series that holds your attention and keeps you guessing what can go wrong next. I really enjoyed seeing the first 4 series. Being an American I find the language very different than what I am used to hearing but it is easy to lean the dialect. Worth the time to watch it! Hope series 5 comes out on a dvd that will play in the US.