Im in the market for a new lens for my Canon XTi. I will be using the lens to take photos of local soccer games and BMX events. My Kit lens just isn't cutting it any more. I have narrowed it down to 2 lens:

http://www.usa.canon.com/consumer/co...9&modelid=7443

or

http://www.usa.canon.com/consumer/co...9&modelid=7337

Please help me pick.....