I can't speak about the differences because I have never used the old type 200, but I do own the 200 NH. I haven't used it extensively for narrow lines, although the first time I used it was for free-hand camo on a 1/72 Tiger tank which was a piece of cake. I'm a lot better these days, and I think I could now dial it in fairly easily for lines under 1/8". When opened up all way, it'll spray very broad patterns like what you'd get from a rattle can. Naturally it does everything in between. Quality of finish is excellent and the atomization seems fine.
Assembly and disassembly is a snap. Un-screw the head (no real need to unscrew the crown), take out the tip and the needle and paint chamber is exposed for cleaning. You could unscrew the needle at point if you want and it's fully broken down.
I think the change was just to give you the range of narrow to broad patterns without needing to change out the needles. As another had mentioned, the needle and head are shared with the 155 Anthem.