Quote Originally Posted by Tarzanman View Post
Nothing wrong with the 70-200 f/4, but at f/4 it will be too slow for most non-professional indoor sports/action. Everyone I know who has this lens wishes it was a f/2.8 when they take photos indoors.

The Canon 70-200 f/2.8 is definitely overpriced. The Sigma is just as sharp (sharper at some apertures) for about $600-$800 less. the Sigma also comes stock with a tripod mounting ring and lens hood.
1. Pricing is your opinion only. Someone asking for lens purchase advice needs facts, and not opinions. I had the Sigma 70-200 2.8 HSM version, and while it was a good lens since I was on a budget a while back ill tell you right now its not as sharp as my current 70-200 2.8 L (IS)

And as far as you saying the 70-200 f/4 would fail in most "non-pro indoor sports /action", I dont think that applies here as the OP stated: He plans on using it largely for motorsports, mostly to get decent pics @ Turner and Gresham and FD when it rolls around.

The 70-200 f/4 would be fine for that, considering his budget and wanting a good quality lens.