Well i rechecked the ISO1600 from what i see the NEX has much more detail in jpeg then the D3100 at for that matter a 600D ,so not sure by what you mean by noise supression,since if the noise suppresion in NEX is high or aggresive granted you will not see less noise but at the cost of detail ,but from what i see i see more detail in NEX .
I also see the the nex having the edge in dynamic range vs canon cameras like 600D
I also see the the nex having the edge in dynamic range vs canon cameras like 600D