I wanted to start a thread for this awesome little lens. I bought it over the 14mm because it was about half the price at the time (due to a sale), and I thought the slightly tighter field of view and extra stop would be better for me, because I mostly shoot people.
There's definitely a decent amount of distortion in the RAW files, but the in-camera JPGs really aren't bad, so it can still be good for landscapes and the like. It's great for people - sharp and fairly quick to focus, and it's so tiny. I ignored it for a while after I got my 23 1.4, but when I put it back on my camera I realized how much I liked it. Before, I just saw it as my wide angle for when I needed a wide, but now I choose it for its character.