My wife is 5'-11" and has a 34" inseam, and was told that she needs a 60cm
bike. The WSF models are all too small for her, and thus she's confined
to
the men's models. I guess my question is a difficult one to answer, since
both bikes are targeted to the same market.

I'm exactly the same size as your wife and ride a Trek 5500 size 58 with a
120mm stem. Suits me very well indeed.
Hjalmar