The extended head lug is "different" at best to someone who was used to the "traditional" look. Riv appears to use it to get the handlebar higher, Sachs does it appears to adapt to the current vogue of stems and associated hardware without resorting to lots of spacers. Note his extensions are shorter than Riv. but his clients want a race like bike.

Beyond that stuff, Riv has a number of models, at least one is USA made and "custom" built. The others are contract production, by good mfgs. So, hard to "compare" directly. Riv makes stuff for currently made parts, Vintage designed for parts made long ago. Riv kind of translates vintage to the modern world in at least one language, Grant's.

I like the old stuff, but I know how to shift and don't race. If I was to race again, I would want as I did back then, the competitive edge, both functionally and to intimidate others. Spare wheels? No, spare bike!