In that dpreview comparison the A7s has the cleanest jpeg image compared to any other camera,So i agree the video quality should be really good like those fish video.
I think Andrew rushed this article.
Actually both the Sony 16-50 and 16F2.8 are soft and crap respectively compared to the Panny 12-35 F2.8.
Except a few primes in Sony only the Zeiss and Sony G lenses are good.
Even the 16-70 zeiss is soft compared to the panny.The 18-55mm kit lens bundled in older Nex is better then those two Sony lenses.