I'm on the verge of buying one too but I'd like some advice from those of you who already have it.
Looking at the samples I found online (here, flickr, instagram, taobao listings) there seems to be an obvious problem with the corners at wide apertures. I can very well leave with soft corners at f/1.8...4 for such a small lens, but I'd like to know how it behaves at f/8 and f/11 in the corners.
By the way, there is a tab that seems to be stickable on one side and small enough not to cover the whole distance scale.
