I liked the concept. Dug the use of music (especially the Snow Patrol joint in the above clip from the Pilot's climax). And thought the cast was mad authentic--in appearance, manner and portrayal.
But I always felt like the element of redemption was almost impossible to believe. Like, how can you really care about these characters when all you see of them is thuggery? Perhaps the moment when the brothers suffered the ultimate wound to their collective humanity (the death of their father, I presume) was the Season 2 reveal. But now that the original 13-episode order has aired, we'll probably never know.
*Pours a glass of scotch*
"Here's to ya, Irish. It was good while it lasted."