I'm upgrading my GF1 and will give up this older body to a family member who's relatively new to photography. As I'll be holding on to the 20mm f1.7 that came with it, I'm currently in the market to purchase a lens for her. She certainly likes the photos that are coming out of the 20mm 1.7, though the price is quite steep. What do you all think of the Sigma 19mm f2.8? Is it good considering the low price? She wants a decent lens that can perform relatively well under low light (which I'm not sure the Sigma is) though I wonder if the Sigma 2.8 can do the job. Any personal experience using this lens? I saw on the buy/sell section of this forum that it's selling for just over $100, so I thought I'd get some feedback from you all. Thanks in advance.