5N vs NEX7 RAW compared.

ISO 6400 compared in Capture One (LR3 doesn't support the NEX 7 yet) with luminance NR and sharpening turned off completely, chroma NR at default.

Notice that the 5N received 1/3 of a stop more light, so results should be slightly biased towards the 5N.

NEX 5N 100% crop, ISO 6400 :

NEX 7 @ 16MP crop, ISO 6400 :

The 5N looks a hair better, which could be explained by the difference in exposure.

Because this is what the 5N looks like at ISO 12800 , to put things in perspective and show what a full stop difference with that camera looks like:

IMHO that puts the whole discussion about the high ISO results of this sensor pretty much to bed.