I think after four episodes it's safe to say that Luck is pretty great. The people that can't get past it "being horse-racing-insidery" are part of the same demographic responsible for Deadwood being replaced by True Blood.
I loved Deadwood. I also love True Blood...and Rome, and Sopranos, and Curb, and Concords, and Boardwalk, and Bored, and Eastbound, and Hung, and Game of Thrones...hell, I even watched that rough ridin' surfer one they put out a few years ago.
Can't get into Luck. The first episode was garbage. I saw nothing in that episode that made me think that there was anything interesting about the show. I don't like horse racing, little angry jockies, gross fat wheel chair bound gambling degenerates, etc. Tough sell.