I am still waiting to find somewhere to buy this lens but I have been gathering as much info as possible about it. My impression so far is that it is an amazing lens. At 80% of the image, there is practically no difference between f/2 and f/8. I have not seen a WA lens that performs so well wide open, the clarity and resolution are simply stellar. The corners are quite blurry at f/2 but what is interesting here is that the blur does not start gradually but the border line between sharp and blurry is abrupt, which is a good thing imo. At f/2.8, More than 90% of the image is awesome and the little vignetting seen at f/2 is completely gone. There is no image improvement when stopping down on the sharp area of the image, it's sharp as nails since f/2 but the extreme corners keep on improving. At f/8 it is possible to see some blur in the very extreme corners but I would say just 1-2% of the frame. There is noticeable CA especially in the corners that can be still seen even stopped down. It is the easy to remove by software kind of CA though. There is a lot of praise about the mechanical part of this lens as well, construction, manual focusing action...etc.