Nuppin is indeed airier than a Narda.
There's no clone of it though, and they just sold out a batch, which happen only occasionally. Maker mostly makes mods. So you'd have to kind of keep an eye out for a used one these days. They are, however, outstanding. Just simple, reliable, exceptional flavor atties...
Not BIG air, nor a big deck or big wire holes. But as I don't need those 3 things, the Nuppin is my go-to all day favorite.
I like the O-16 too, but it's a little bit tight. And I like the Narda, but wish even that had a TINY bit more air (and didn't whistle).
Looks a bit airier than a NarDa and I can co-exist with one of those.