Just one question: at what focal lengths does it become usable on the larger formats? 
FWIW, the lens isn't exactly brand spankin' new: Lenstip has reviewed it almost half a year ago: http://www.lenstip.com/index.html?test=o...est_ob=470
FWIW, the lens isn't exactly brand spankin' new: Lenstip has reviewed it almost half a year ago: http://www.lenstip.com/index.html?test=o...est_ob=470