Both seasons are a little slow to get going but it's quite enjoyable after that.
The show is visually appealing and has a very good cast. The contrast between the opulent lives of the rich of New York around 1900 and the squalid lives of the poor couldn't be more stark. The show is in the Gothic Horror genre I suppose and deals with awful crimes committed by psychopaths. Not a show for those with more sensitive and gentle natures.
There are some loose ends and quibbles with logic but that is to be expected these days.
7/10