The Naxo NX21 AT binding is not a bad product. It’s a touring binding that’s stout enough for resort use, and which has a touring mode so well designed that it makes skinning in alpine boots bearable. This is the binding, mounted on last year’s BH District:
One of the marketing points for Naxo bindings is that the mount floats on rails, without any fixed points to the ski, which would affect flex. This is not particularly important, given that added stiffness underfoot is rarely a bad thing. Well, it wouldn’t be a bad thing if it didn’t open up the binding to torsional flexion.
Observe: The toe piece, ski unflexed.
The heel piece:
And the same phenomenon:
It’s extremely difficult to show in photos (especially taken solo), but the construction of the binding (two longitudinal rails connecting the toe and heel) lends it to extremely easy twist. That means that no matter how stiff your boots are, the introduction of flex to the ski (as occurs in ordinary skiing) results in substantial rotational flex in the binding, resulting in a very sloppy feel. I noticed something during last season, but considered that maybe it was in my head. I have now proven to myself that it is real.
The new Districts (stiffer than last year, with an added layer of metal) that I have will be mounted up with Marker Dukes, which by several accounts are even more laterally rigid than alpine bindings, and have a substantially lower stack height than either the Naxo or the Fritschi. That should be complete before long, and I’ll be back with a similar subjective test.