Summary: Much sharper and faster than the sony e-mount kit lenses (as you should expect from a prime lens). Compact, and makes an excellent "walk-around" lens. 45mm equivalent is very nice for general use, and it'll fit in a jacket pocket easily. A great addition to the e-mount lineup.
Summary: Quite clear, little distortion but moderate vignetting in certain conditions. I shoot wide open most of the time, and I'm quite pleased. That being said, with the widest aperture being f/2.8 this lens isn't particularly fast. Don't expect to see in the dark or luscious bokeh. AF is quick, the build quality is nice and I like operating the focus ring. It's also extremely quiet. For the price, you really can't go wrong.
Summary: It's a fairly nifty lens. After using it for a day I was able to figure out how to get any shot I needed. I wish the minimal focal distance was shorter, but it's not so bad that I could complain (after all this isn't exactly a macro lens). I'm coming from using the Sony SEL50f1.8, and that one is certainly a superior lens, but only if you can live with its very narrow field of view.
Excerpt: I bought Sigma's 60mm f/2.8 DN to use with my Olympus E-M10. The results from the 60mm were excellent, so when the 30mm f2.8 and the 19mm f/2.8 went on sale, I ordered both. The 30mm has not disappointed and I can't believe Sigma is selling this lens so cheaply. The images from the 30mm are very sharp and have excellent image quality.
Pros: Consistent Output, Durable, Easily Interchangeable, Fast / accurate auto-focus, Lightweight
Summary: This lens is great! The images are sharp and the bokeh is smooth. It has a quality metal body that is finished nicely that doesn't keep fingerprints. Though, the metal finish is a bit slick and I would prefer a knurled or geometric surface to the slick one. The smooth rotating focus ring more than makes up for that slick surface, though. It is ideal for manual focusing when shooting video. And, the fit onto the MFT body (a GX1 in my case) is tight with no wobble.
Excerpt: I use it with Sony a6000. This lens is much sharper and faster than the standard 16-50mm that comes with the 6000 as a kit. It certainly comes closer to exploiting the real possibilities of the a6000 than the kit lens. It may not be the best lens available, but considering the price, it is a very good deal. It makes a disconcerting rattling noise if you shake it (gently) or when you turn the camera on, but the auto-focus works without fail.
Pros: Consistent Output, Easily Interchangeable, Fast / accurate auto-focus, Lightweight, Nice Bokeh