I'm doing some sports photography for Georgia Tech next year and I've been needing a replacement for my 75-300 for a long time (It's such a soft turd). Forever I'd been going back and forth between the canon 70-200 f4, sigma 20-200 2.8 and the canon 70-300 IS (though it's out of stock everywhere until sometime in August or later). I had forgotten about the Sigma 100-300 f4. I started reading reviews on it and it can be had new for about $800. About half the sports I shoot will be outside, the other half inside, body is a D30. I thought a lot about getting the Sigma 70-200 2.8 with a 1.4x converter because I need to get near 300mm but it would end up being a bit more expensive in the end. 300mm is the most important factor in my decision. I guess I just wanted to tell OT and see what you all thougt about it. And of course I'd like the canon 70-200 2.8 IS, but I just can't afford that right now.