I bought the Julbo Blast S3+ in blue-green at the same time as the Smith Drake, so I provide some comparisons here. My evaluation is based on wearing the Julbos on a hard 40 mi ride, an easy 20 mi ride, and subsequent hanging out for a few hrs in on a sunny day with mild haze to compare the Blasts and Drakes directly.
First, the Julbos look super-cool in the blue-green! They fit my somewhat large face quite well, the lenses are stunning aesthetically, and the frames are have a nicely sporty look without being obnoxious. Given my advancing age, their appearance is slightly too swept back, athletic looking for wearing about (e.g., window shopping, cafe dining), except maybe at the beach or other semi-athletic situations. The frames have a matte finish and flex very nicely. Contact points are very comfortable, and my GF said they "feel like air!" Overall, the Julbo Blasts have a high quality fit and finish, something I cannot say about the cheapish-looking arms of the Smith Drakes. Nonetheless, the Smiths look better on my big head, particularly for off-the-bike use and so are slightly better shade for general hangin' out.
On the bike, the shades are very comfortable, at least under the ideal conditions of my first ride. Optically, the glasses performed very well in my limited trial. At less than half the cost of the Smith Drakes, I found the lenses to be nearly equal to the polarized Smiths. My vague sense is that maybe the Smiths perform slightly better optically, perhaps due to subtle effects of the polarization, but there were no obvious differences, despite my efforts to find something, anything. The Julbos are quite competitive optically.
I compared viewing area and found important differences between the Julbo Blasts and the Smith Drakes. The Julbos provide increased peripheral vision because of their swept back shape. However, because of the close-fitting frames -- and likely exacerbated by my long face -- I can see considerably more of the top of the Julbo frame than I do of the Smiths. I didn't consider the view of the frames as any hinderance on the bike (or even realize it) but just noted the difference in my side-by-side comparison off the bike.
I cannot comment much on ventilation and performance in hot weather because the early fall conditions are already quite mild here. On a harder ride, I didn't have any issues with sweat dripping onto the lenses and pooling in the frames, but it was too cool to really evaluate how they would perform in the heat. As I mentioned in my review of the Drakes, the Smiths perform quite well with sweaty and rainy conditions because of coatings that seem to reduce droplet sticking.
In summary so far, Julbo Blasts are winners! Styling is great for athletics, fit is wonderfully comfortable, and optical performance is similar to glasses costing more than twice as much.