Well, I couldn't care less who makes the lens, if it gives the results I'm after.
I was hoping after returning a Zeiss F/2 35mm that the Sigma would be better.
It is sharper, yes, but not in a jaw-dropping, oh my god way.
That honor belongs to the humble Fuji 35mm F/1.4 mounted on one of their X-Trans equipped cameras, which for $600 is really the deal of the century.
Many have tested this combination against a Leica M9 + Summicron 50mm and cannot tell which is which.
For what it's worth, the new 40mm F/2.8 shot alongside the Sigma 35mm @ F/2.8 on a 5D MK3 is almost as sharp.
It has a cooler tone, while the Sigma is more warm, but zooming in to max in Lightroom on a 30" monitor doesn't show the Sigma I have to be that much better.
Anyway, I'm trying a 24-70 II next, to see if I can find that magic I'm looking for.
Maybe I'll just have to buy a Nikon D800E...