I got
10 x 480 8Gb Reference
and
6 x 470 4Gb Reference

480s @ 30.5Mhs
470s @ 27.5-28Mhs

The price difference between the 470 4Gb and 480 8Gb is around 117USD here where i live.
I bought the 480s early and if i had knew that the 470 4Gb could do 27-28Mhs easy i would have gone all in on 470s instead.