One of the very few extra-wide legacy bargains. I haven't compared it directly against the SEL16. (I did compare against a brand new Tokina 11-16 and I must have received a bad copy because the zoom got trounced.) Sharpness seems pretty decent. My copy of the old prime may be slightly decentered - the entire right edge stays slightly mushy, even at f/11. Left side looks great, though - all the way to the corner, baby! (One solution w/ my copy would be to think in a more square-ish format like 4:5 while shooting, aim right & crop the mess away.) CA rears its ugly head but is swiftly dealt with in Lightroom. No sign of magenta cast in the corners on the N7 - least not to my untrained eye. All in all, I'm pleased with the lens - it's a nice physical fit on a NEX IMO. It's certainly holding me over until some more enticing extra-wide solutions emerge.