I dissagree, i believe it's both.
They list the following discs lower than or same as princo, which is wrong:
CMC / MAG
GSC00x (gigastorage, which they don't even list this manufacturer name)
Discs listed possibly too high compared to other discs listed lower:
They don't list 16x media. They don't distinguish between some generations of MID's which can be VERY significant e.g. CMC MAG AF1 vs AE1.
Maybe this is just a matter of opinion, but i definitely wouldn't recommend trusting that chart too closely.