  We review the results on representing the differential cross section for
W-pair produciton, including W decay and hard-photon bremsstrahlung, in terms
of a Born-form approximation of fairly simple analytic form. The result of the
Born-form approximation are compared with full-one-loop results. The emphasis
is on the energy range of future $e^+e^-$ (or $\mu^+\mu^-$) colliders.
