It's class.
It's like the sopranos, set in California.
Characters are great, the only thing that lets it down is Ray's wife. They have clearly based her on Carmela, but she is annoying as fook.
John Voight is the best thing in the show, but Liev Schreiber is quality too.
I'd be surprised if you were disappointed, it's one of the best about at the minute imo.
I find Ray Donovan closer to the story of a grand theft auto game than the Sopranos. Still quite enjoyable though.