You know you want the 2.8L IS IIAfter today shoot I decided on Monday I will buy the 7D. I found the 50D using the center point focus was not as accurate as I thought it would be.
Now comes the additional cost, should I add the 70-200mm F2.8 IS II. Think I want to keep the 70-200mm F4 IS because it so light and can easily be used on the 5D II as a street photography. The only thing is the weight I went to the store a few weeks ago and after 30mins my left arm could feel the pain.
To me the 5D II with the 6 assist focus points in AI Servo was more accurate when the subject moved away from the center focus point.
On the 50D I would say about 90% was in focus and the 6.3fps was good.
Usually when I'm shooting Soccer I use a monopod attached to the lens (the 2.8s come with the lens mount as opposed to the $200 option with the f/4's) so weight is not as much of an issue. The 2.8 balances nicely on a monopod with a 1D series or a 5D/7D gripped.