All these threads of male vs female.
It was pretty much agreed, Serena is par with the best of the 5.5 bunch.
So if that's even remotely possible, Date cannot be a 5.5, since she is not nearly as strong as Serena.
I've already conceded Date would crush a pusher, weak hitting 5.0. Date would match up pretty well to a SOLID 5.0, and usually win, but that depends on experience by both players.
But against a RISING 5.0, one who has the tools to go straight to 6.0, it's not so clear cut.