I used to use this lens more than any other. I only moved away from it because I found I prefer longer focal lengths. The colors and rendering seem to give some magic to the pictures, something apart from sharpness and contrast that's hard to define. Your picture of the bull is a perfect example of what I love about this lens.
Handling is also nice. It's tiny, as you say, and I like the aperture ring up front. I use it with an A7r.
I've never noticed much problem with the corners, even on full-frame, but I rarely use it wide-open. I think this one was at f/4:
As noted, flare resistance is minimal, but the way it handles extreme backlight is pleasant to my eye.
Out-of-focus areas are surprisingly pleasant for such a wide lens.