Seeing as the Xi2 is pretty even with the WS-60, and the WS-70 is generally a little better than the Xi2, except in clear roads, where the Xi2 is quieter and more civilized.
Either way, the tests can fluctuate pretty often, and in any case, the Xi2 or WS-70 are a generation and a half or two generations ahead of my old WS-50's and Dad's old Graspic DS-1's.