OK, fastest current production lens. ;-)
Still, it is pretty cool. Think about it; the aperture stop (the proper term for the stop that limits the bundle of light rays entering an optical system) is larger than the focal length! This is an amazing optical accomplishment. I'm eager to see shots with this lens. The MTFs will be interesting to study as well. That, however, is as close to this rareified class of lens this commentator will ever get.