Interesting that it is faster on the track according to the author. The only acceleration performance category where the M6 failed to beat the 575M was the 100-200 km/h., please correct me if I am wrong. If that is the case, the type of track would have a significant influence on this comparison.
F-cars are cool and all, but the GT types 550/575/612 do, or will take HUGE depreciation hits (355/360/430's do much better at holding value). I personally never understood the Ferrari GT thing. For the kind of money they get for them, there are so many other options available that do a better job for less cash.
Here in the U.S. the 575M will be 2 to 2.5 times the price of the M6!

For that kind of premium it **** well better beat the M6 at something!!