That list is wrong and compiled by someone who doesn't know what they're talking about. the 8600gt is just a 9500gt with slower clocks and a larger die and is faster than a 9400gt in everything, even if the 8600gt only had ddr2. remember, when it comes to GPU nomenclature, the important part is generally the second number in the name, i.e.
6 is higher than
4, so the 8
600 is superior to the 9
400. this is almost always the case as long it's only a one generation gap between cards (the first number denotes generation - in this case
9 is only one higher than
8) and a greater than 2 gap between second numbers. the 8600gt has double the amount of stream processors of the 9400gt - 32>16, double the texture processors - 16>8 and almost double the memory bandwith - 22.4>12.8. the only thing that would be a slight concern about the 8600gt would be the size of the ram on it, although i say slight because it would probably be quite rare for it to have a large negative effect on performance. most of the time the processing core would be overwhelmed before the ram would cause a performance destroying bottleneck; using your example Nintendo Maniac in crysis the ROPs wouldn't be able to handle tons of AA anyway.
anyway, just to show that i'm not talking out of my behind, proof:
ASUS EN9400GT
