Don, I'm heavily biased to the old "tried and true" system. When the NH style head came out, it was billed as an improvement that was supposed to do away with the need to change tips and needle sizes. The double taper on the needle was supposed to "do it all". And like most one size fits all, it didn't actually fit all sizes well. The transition between fine line and full bore output was very hair trigger for many people (ME!) and it didn't do the fine lines as well, so Badger brought out different tips and needles to achieve that goal. Since the design was supposed to eliminate that, I consider it a failure over the older system. In my mind, the older system may have had that pesky washer, and a wrench to tighten (though I never use mine, finger tight seems to work fine), but the fine did fine lines and the medium does medium lines, without the WHOOPS TOO MUCH PAINT! issue that people have reported on the NH style airbrushes (especially the 175 Crescendo, which was designed with the T-shirt artist in mind).
From the information that has been provided to me from numerous manufacturers (for that mythical airbrush guide that has been lost on my back burner for months!) the longer the taper, the finer the lines. The double taper of the NH head seems counter-productive to that goal. Now, as you say, the average modeler doesn't need that fine of a line and the Anthem, Patriot and 200NH are all decent airbrushes for that use. And with some practice one can achieve wondrous things, just as one can do with the venerable Paasche H. I'm an aging (not yet old) dog, and already I'm finding learning new things to be frustrating. I'll stick with the old fashioned ways.
I do note that when Badger brought out the Renegade line, they went back to a single long taper.