I can help you. I'm a sports photog who specializes in cycling. I shoot with a 1D (the "classic" or "Mark I") and a 40D.
The AF speed and accuracy between the two are like night and day. The 40D doesn't even come close. My keeper rate with the 40D is like 80% within acceptable focus. My keeper rate with the 1D is like 98%. Yes, out of 100 photos, I have to go looking for shots that are oof, and yes, they are hard to find. I'll be lucky if I find two or three.
As for the 45-point AF tracking, I can't help you with that. I use Single-point only 100% of the time. I use the topmost point (in both vertical and horizontal orientation) and set my dot on the riders face, or, if they are further away, I use center-point only. Using all the points, especially for a subject as large as a human, is for wussies. I can see using all AF points for a smaller subject- suck as a bird in flight.
Since you are asking about a Mark II, the AF system is even better than the one on my Mark I. The only downside to owning a 1 Series body is that you'll never go back to the cheaper pro-sumer (xxD) line again.
| Byte size: ZERO | Content warning: NOT AN IMAGE |