The Leggero from Ombraz is their slightly larger, more 'traditional' shape. Otherwise they are functionally identical to the Dolomite and Classic frames, which is a good thing, because these things are a genuine game-changer in certain situations. It's great to see someone doing something genuinely different in the overcrowded sunglasses space and these are well worth trying out to see if they work for you.
I have fairly sensitive eyes and have tested both the brown and grey polarized lenses. I can't say I'm particularly good at detecting the subtleties of sunglass lenses, but like most, I can tell instantly if I have good or bad (usually cheap) sunnies on, and these are on the quality end of the scale. The grey is they slightly darker of the two, but I actually prefer the brown lens as it feels a more comfortable tint for most situations. The grey seems a little more comfortable dealing with glare from the water or on snow, but the brown comes up trumps when the light gets flat. The differences are small, so I'd go with grey if you only wear sunnies when it's a perfect day, but the brown if you're more a sunnies everyday guy like me.
The Leggero is a slightly larger frame in terms of footprint (faceprint?) but I find both them and the Dolomite equally comfortable, and I have a fairly average-sized face. I think it's is more a question of style which model you choose but I am impressed by how comfortable all the frames feel on the face. If I had to choose, I marginally prefer the Leggero for skiing because it blocks a little more wind. It's important not to overtighten the cord because then the lenses can end up pressing uncomfortably but that would be on you, not the glasses themselves. I actually find the frames more comfortable on the nose than most sunglasses.
The lenses and frames of Ombraz are great. But their defining feature is, of course, the armless design. And there are major positives but they can be a bit fiddly. The negative is that the cord is more complicated to take on and off if you are wearing a hat/helmet. That is doubly true if you're wearing the ever-present in the 2020s facemask. You do have to take off your hat/helmet every time you want to take the glasses on and off (assuming you aren't some kind of cord over the hat sociopath) and that makes popping in to the shops or whatever a bit annoying.
However, the flipside is that these babies are staying on no matter what you throw at them. For outdoor pursuits, that is a genuine game-changer. When spinning in the park, getting off-axis, these things stay on like goggles. I have always preferred sunglasses and thanks to these, I only wear goggles when it's bitterly cold. But I notice the difference most when I'm climbing on overhangs and especially bouldering. I always like to have sunglasses on when outdoors because of the aforementioned eye sensitivity, and these have really made climbing a whole lot more pleasant. No chance they are moving around and distracting you when going for a bigger move or shaking it out. I could even wear them deep water soloing with no risk of them coming off.