Interesting design. Bizarre, even.
Might take some getting used to, and as Rick suggested it might be more awkward for negotiating tough edges. I wonder if the bodies are cast or rolled/milled? Personally I prefer not to use cast ascenders for caving if I can avoid it. I can't really see how the safety/lock open for the cam works, but I assume there is one.
On the positive side it looks like you can still cup your other hand over the top to help with good Frog technique. On the negative side I'm thinking the rope sliding against your palm would be really annoying for those who prefer to use their ascenders without gloves (as shown in the photos). The absence of an upper attachment point is a little disappointing too - this can add options when you need to do "other things" with your ascender (haul cam or PCD for rescue, etc).
I like the look of foot ascender with the rigid stirrup piece under the foot. I wonder if this setup will provide improved ergonomics over the Petzl Pantin? (It would be nice if it does.) I love how they show the shiny new ascender and rope on an old grotty boot. Very cool!
Hunter - I think the cams must be steel or some composite. I can't imagine they'd be an aluminum alloy. I think Scott's right about a few things being lost in translation. They probably tried to use a program to translate it instead of a real person. I'd be reluctant to describe most mechanical toothed-cam ascenders as "belay devices" but I think "bloccanti" is supposed to mean blocker/jammer/ascender rather than belay.
I'd give these a try, especially if someone else owns a set and doesn't mind other people borrowing them.