Well, I'm still sticking to my view, but everyone is entitled to their own. There is more to the 6xx series than just the EM64 memory manager, unlike 5xxJ (that has just exactly that).
The Prescott core always had 64bit hardware built in it, is was just disabled when originally released. Credit due, the 5xxJ series can address memory in 64bit mode and not do much more, but the 6xx series can run fully AMD64_x86 code.
I don't get how it can do some 64bit operations and not all, programs are compiled to AMD64_x86 code or Ix86 code, one or the other, not a mixture of both. (I mean here that the program itself cannot be made up of two types of code, not that the CPU can't handle two different, 32bit and 64bit applications at the same time). An example of this would be the Windows XP 64 bit OS, I'm sure that most, if not all the 64bit intruction set would be used in it. This goes for the safotware that was used to benchmark the CPU's