Shockingly bad. I think this is supposed to be a comedy drama but it's utterly ridiculous.
The wedding scene in the first episode was enough to make me give up there and then. Ridiculously violent for no good reason and of no real use to the plot.
The prison scene was completely cliche ridden, all the characters were two dimensional and poor Freddie Highmore on a hiding to nothing with his very poorly written part. One of the worst things I've seen for a long time.
Check out The Veil on Channel 4 instead, far better.