Yes, they claim minimum of 640 fill or higher. However, there's a lot of speculation that they are probably not using the American standard of fill power calculation since the down appears such high quality that it's more like 750 by the American standard.
That said, it is a pretty skinny jacket so they aren't using that much fill either. Competitors in this space like the Patagonia Ultralight Down Jacket (much more expensive, btw), appear to have similar loft but a noticeable amount of overfill.
Apparently they are using nice fabric, from Toray.
Some more information can be found on BPL...