Passes the Real World test just fine
I received the XS last week and took hundreds of photos with it, both indoors and outdoors this past weekend. I then imported the photos into Lightroom 4, so it's possible that LR4 compensated for any lens irregularities. In any case, I saw some fantastic results in terms of color, clarity, and depth of field. The 40mm focal length was quite liberating. I'm just an enthusiast and not a pro but I love this lens. And it's so tiny there is no reason not to carry it in your bag at all times.