If I was to use The Digital Picture as a guide when buying lenses, I would have my camera body and no lenses at all. I tested all of my lenses and compared them against TDP results, and honestly, I really don't know where these guys do get their stuff from.
it's fairly accurate from my experience. Sometimes they are off, but I do think they put in effort to correct.
I do prefer photozone and lensrentals more, even dxomark. TDP is certainly good for quick references, but hardly the final word.

