I know you probably want to buy local, but you can save up to $300 by purchasing the f/4 IS version on line. http://www.amazon.com/gp/product/B00...edigitalpic-20 or http://www.amazon.com/gp/product/B00...edigitalpic-20.

I use the f/4 IS and absolutely love it. I used it for a couple weddings and it performed flawlessly. That being said, I have never used the 2.8 version of the lens, but with the savings, IS, and overall image sharpness, I would go for the f/4 IS version.