Well, I got tired of the dealing with the poor AF tracking ability of my Minolta 7D. So I went out and bought a Canon 30D with a 400 f/56.L USM to use on flying birds. I've been shooting Minolta since the late 80s so using a Canon will take some getting used to. Initial impressions are that the Canon's AF tracking abilities are on par or better than my old Minolta Maxxum 7 which to me means a significant increase in keepers now. I never did understand who Minolta could send a DSLR to market with an AF system that was worse than what they had in a film camera produced 10 years ealier. Weather permitting (snowstorm right now) I will give the Canon gear a proper wringing out tomorrow and post some images.