I myself use the lens on a Sony A7R with a Canon EF Adapter (this lens, there is no (F) E-Mount version) and am very excited about. The effective sharpness (ie existing image information) is even at maximum aperture to be described as excellent so you can use it at 1.4 hesitation. Photos in this combination can without compromising even 1: 1 are considered. Visible distortion towards the edge so far I could discover in any of my pictures (and I must say that I have photographed any test charts or house walls because I do not think much of it). The background blur (the bokeh) is soft and quiet which makes it exempt a lot of fun making objects.
There are only three things that stand out to me are a bit disturbing: *) Lens is prone to side light (especially at full aperture). *) The enclosed sun visor seems to be not just the yellow from the egg. It is quite 'hakelig' to mount and helps very little. *) At maximum aperture, it tilts in High Contrast situations CA. It is (especially considering the price) is not particularly bad but available.
Conclusion: For me, a very good lens that I would buy again at any time.
