today i had the chance to test the Sony A7R.
all i can say.... I WANT THAT SENSOR IN A CANON!!!
pushing the shadow on ISO 100-200 images introduced nearly no noise.
images from canon looked like S___ when pushed about the same amount.
really, the difference on noise introduced is like ISO 400 vs. ISO 3200 images...

for lansdscape images, where i often have to lighten the shadow areas a bit, that´s a great deal.
the sensor at ISO 100 really is a dream.
personally i don´t care about ISO beyond ISO 3200 (i can´t sell such images anyway).
the EVF is really good too. still not perfect but an absolutely useable EVF.
i must say i am impressed by it´s sensor... and in parts the EVF.
a canon 5D MK3 with this sony sensor.... what a fantastic camera that would be.
canon builds the best overall cameras in my opinion.
but this sony sensor shows that canon has much room for improvement.
of course i knew the tests done with the D800.
but using this sensor myself with LR today was an eye opener.