A note from Wikipedia says: In 2003, a three-episode OVA mini-series titled New Fist of the North Star was produced by OB Planning. based on a 1996 Hokuto no Ken novel Jubaku no Machi. An English dub version was produced by ADV Films in 2004.
Well, you can't have 'a first' more than once. And so, for those reasons alone, this isn't quite as good as the original series - despite having all the key/signature elements in place.
I bought the first DVD (the first hour-long episode)and thought that was it. I didn't know the story arc had two more parts. It felt like a complete story. I would say personally, it seemed like they made parts II & III after the fact since everything kinda lessens (in impact) after the first movie.
All three are worth owning, but I could imagine this being a single 2 hour movie with some of the side fluff cut out. It does justice to the franchise which can't be said for most modern follow-ups.