It was good... not sure what the guy who said it was too slow was expecting, just non-stop violence? You have to build up the characters a bit in the first few episodes. There was a bunch of violence throughout the show anyway.
It was also cool to see the different famous mobsters, seemingly before they become household names (Capone, Luciano). It will be interesting to see how these guys evolve, especially Capone. I didn't realize he would be such a major character (and still not sure he will be). I think they just didn't want to sell it as a series/show about Al Capone, but more so Prohibition-era Atlantic City in general, and more specifically Nucky Thompson.
Not to mention the production value- the scenes were gorgeous in HD.