20d vs 5dmk2 in focus

I'm still undecided on which body to buy.I have a 20d but want something that focuses fast and accurate on birds,sports, etc.I also would love a full size sensor too.I can get by with the focus of my 20d and my question is will the 5dmk2 be as good or maybe better than the 20d.If so I would buy it.Thanks.

5dII for birding and sports? Nein nein nein... 7d my friend. I know you want full frame, but honestly youd benefit more from a 7d in terms of autofocus and speed.

The 5D center point is pretty good at tracking (with the AF expansion points), but I would think the "reach" of the 7D and additional AF options would be very helpful. The best option might be a used 1DIII, which should be in the price range of a 5DII.