27 MH/s from a 1060 3gb?

I just ordered 6x 1070 for ~$400/each and 4x 1060 6Gb for $260 each.

Should I just return the 1070's? I have one running now and it's pulling about 31 MH/s

If I were to keep the 1070's which are better EVGA black edition vs FTW gaming. I wonder if any of them come with Samsung memory any more.