Let me get the "but" out of the way: the narration is so full of superlatives about the city the praise becomes tedious and borderline annoying.
Now. I missed the series when it was on PBS and thus took advantage of a lull in my other responsibilities to watch the series. The Burns never cease to amaze: the breadth, the scope of their research and yet thir ability to cover the highlights without missing important details is nothing short of genius. My particular interest in the series came from my involvement in research on immigration to the US for a play of my own (my drama on the subject is being produced this month in Columbia, SC, but I intend to expand my focus with the next play). I don't think I could have gotten a better sense of what early NYC was and what it has become over the years if I had spent a month in a library.