  We use ${\cal N}=2^*$ and cascading gauge theory holographic models to
extract the general features of the gravitational susceptibility $\kappa$ of
strongly coupled nonconformal quark-gluon plasma. We show that in theories with
a relevant coupling constant the gravitational susceptibility is
renormalization scheme dependent. We propose to use its temperature derivative,
i.e., $\frac{d\kappa}{d\ln T}$, as a scheme-independent characteristic of a
QGP. Although $\kappa$ is a thermodynamic quantity, its critical behavior can
be drastically distinct in the vicinity of seemingly identical thermal phase
transitions.
