Just last week, I traded my 28-135 f/3.5-5.6 to snsgraphics for his Sigma 24-70 f/2.8. I really missed the extra reach this weekend, but enjoyed the 2.8. I opted for better lowlight than for reach. I have to admit. It's weird getting used to Sigma's backwards zoom adjustment. Then again, to Sigma, it isn't backwards. I'm hoping to pick up my very own 70-200 2.8 (thanks for the rental lensestorent.com). Darn you Michael, I don't want to send it back now.