Interesting post by New Zealand based photographer Andrew S. Gibson. The almost 4 years old Canon EOS 7D (price & specs) is still an outstanding DSLR, with an advanced AF system not previously seen on a Canon APS-C sensor DSLR (and still not featured on any other Canon APS-C DSLR). The AF of the EOS 7D is more advanced than the one sported on the EOS 6D. If you want a more sophisticated AF system you have to go at least for the EOS 5D Mark III.
The EOS 7D sports an 18 MP sensor, a body with environmental sealing, 8 fps, a viewfinder with 1.0x magnification and 100% coverage, a dual axis electronic level, and a highly advanced AF system. What is so special with the AF of the EOS 7D? A lot. To begin, it has 19 focus points, all cross-type. To compare, all entry level Canon DSLRs and the X0D line-up feature a 9 point AF system. The picture on top shows the difference between the AF of the EOS 7D and the conventional 9 points AF system. The AF of the EOS 7D is highly configurable, for instance there is “Zone AF”, i.e. the 7D’s AF points can be grouped in 5 zones (pic below).