  We compare exact results from Pestun's localization of SU(N) N=2^* gauge
theory on S^4 with available holographic models. While localization can explain
the Coulomb branch vacuum of the holographic Pilch-Warner flow, it disagrees
with the holographic Gauntlett et.al vacuum of N=2 super Yang-Mills theory. We
further compute the free energy of the Pilch-Warner flow on S^4 and show that
it disagrees with the localization result both for a finite S^4 radius, and in
the S^4 decompactification limit. Thus, neither model represents holographic
dual of supersymmetric S^4 localization of Pestun.
