I have the a6000 and the Sony 20 mm. I like it a lot, especially the 'pancake' size: small and convenient.
In terms of image quality, I usually use this lens outdoors where there is adequate light to shoot at f4.0 - f8.0 and thus the corners are managed a bit better. I shoot in RAW and develop, and the software for Capture Pro 1 helps any distortion etc.
Although i do not use the jpg much I am of the impression that the in camera software does a good job of managing distortion.
What does all of this mean... shoot a bit wide, knowing you may want to trim around the edges. And remember with any wide lens, use your knees to adjust the horizontal perspective (don't tilt if you dont have to).
happy shooting. I
