DxO-mark measures sensor characteristics only. In that regard it seems that NEX 7 is pretty good, but Canon is a bit handicapped in DxO-mark regarding DR at low ISO.
Michael is absolutely right about lenses mattering most. A smaller sensor will make heavier demands on the lenses.
Perhaps Michael has the opportunity to compare the NEX 7 with his Alpha 900, that would perhaps be a valid comparison.
you can see a test shot comparison at all ISO between the 2 cameras, at DP review.
IMO, the nex 7 shows a little more crispiness than the a900.