I have pseudo-used the Grivel Air Tech Light in a shop yesterday. I have strapped the crampons on my Montrail Vitesse and "walked" on a wood board they had for crampon tests.
I picked the crampons from the shelf and was immediately impressed by the weight. Amazing! I am used to waterfall ice and alpine climbing crampons, so the difference really shocked me. The Grivels feel lighter than the Stubai, which is of course confirmed by manufacturer weight.
However, the points look very aluminish and dullish. I fear they will not bite into hard ice too well. The metal seems very soft and rounded compared to steel. I would place Grivel's soft aluminum at the bottom of the hardness scale, followed in the middle by Uralalp (Ushba) Altai ice axe titanium, topped by regular forged steel.
I wonder if steel would be better for late-autumn / early spring mixed conditions: not enough ice and snow, still a lot of rock sections.
The Grivel extender bar flexes freely. The crampon nicely follows the flex of my Montrails, in contrast to very rigid Stubai Ultralight.
However, as suspected, the problem is with the binding. Grivel and Stubai clearly designed their bindings for the stiff hiking leather boots. Grivel's binding connects webbing from the toe counter to the heel counter. When I move the foot around, the crampon flexes with my trail runner and reduces the distance between front and back plastic counters, but the webbing binding does not shorten accordingly. Loose webbing hanging around and space between crampon and shoe do not inspire confidence. Of course I am spoiled by tight crampon to boot integration of climbing combos, but even with a sane dose of realism, I would be afraid of losing the crampon on the way.
In contrast, Kahtoola dissociated front and rear webbing. I presume Kahtoola's binding should normally follow boot flex.
So, as some of you suggested, I think that the Kahtoolas will work better with Montrails, precisely because of the binding. I am waiting to hear Rick's opinion on the steel Kahtoolas, but I guess Kahtoolas are a better solution for a flexible and light trail runner.
ANATOLY IVANOV PHOTOGRAPHY / DESIGN