  We perform a new and accurate study of the dependence on cosmological
parameters of structure formation with local cosmic strings. The crucial new
ingredients are the inclusion of the effects of gravitational backreaction on
the evolution of the network, and the accurate evolution of the network through
the radiation to matter transition. Our work re-iterates the fact that
expanding Universe numerical simulations only probe a transient regime, and we
incorporate our results into the unequal time correlators recently measured. We
then compute the CMB and CDM fluctuations' power spectra for various values of
the Hubble constant $H_0$ and baryon fraction $\Omega_b$. We find that, whereas
the dependence on $\Omega_b$ is negligible, there is still a strong dependence
on $H_0$.
