Hello all....I was looking for some help with Nikon products, 2 of my local dealers seemed to be awfully uniformed about the product so I'll ask here! I've been shooting motorsports for ages and currently have a Canon 40D with 3 lenses with USM focus motors. The results are excellent, both camera and lenses easily keeping up with cars moving as fast as 200 mph. The 10.1 mp of the 40D is also just right. What does Nikon offer that can focus just as fast and give me the results I'm getting now? My current focal length lenses are 15-85, 70-200 F/4, and a 300 F/4. Thanks in advance!