Upload & Sell: On
Yeah, I actually agree with the points myself, and even expressed the same "WTF, Sigma?" thoughts when this and the 30mm were announced. However, I view the lens as more a competitor to the Olympus 17mm f/2.8 than the Panasonic 20mm f/1.7. If you don't have a wide/normal and want something fast and small, the 20/1.7 is your lens, hands down.
I bought this lens for three reasons.
1) I have the PL 25/1.4, and prefer it overall to the panny 20/1.7 (I owned the 20/1.7 for some time and sold it when I got the 25/1.4). I will still use that as my main 'normal lens', for sure.
2) Sometimes I still want a wider prime, in the ~35mm range, but I don't shoot enough in that range to make it worth plopping down the $500 for the 17/1.8 or to rebuy the 20/1.7. Also, the extra 1mm is actually noticeable, and the lens feels more like a 35mm in use than a normal lens.
3) I had a $100 Amazon gift card and $50 from my grandpa for my birthday, and the lens went on sale for $150 over the holidays. I didn't really have anything else I wanted to buy, so I thought I'd give it a try.
The lens is significantly better than the Oly 17/2.8, and Lenstip shows it to even be sharper in the center than the 17/1.8. While optically, it's not going to best the 20/1.7, and it's a stop and a half slower...and a little bigger, it's still very sharp, relatively small, and the AF is much faster and quieter than either the 17/2.8 or the 20/1.7.
So, ultimately, the price was the main driver, but it's a very good lens for the price. I think at $150, it was well worth the money. At it's regular price of $199, it's still worth it, but not by as big a degree. If it were $250 or more, I'd just stock a little more for the 20/1.7.