  We discuss the optimal setup for a low energy neutrino factory in order to
achieve a 5\sigma-discovery of a nonzero mixing angle \theta_{13}, a nonzero CP
phase \delta_{CP}, and the mass hierarchy. We explore parent muon energies in
the range 5--16 GeV, and baselines in the range 500--5000 km. We present the
results in terms of the reach in sin^2\theta_{13}, emphasizing the dependence
of the optimal baseline on the true value of \delta_{CP}. We show that the
sensitivity of a given setup typically increases with parent muon energy,
reaching saturation for higher energies. The saturation energy is larger for
longer baselines; we present an estimate of this dependence. In the light of
the recent indications of a large \theta_{13}, we also determine how these
preferences would change if indeed a large \theta_{13} is confirmed. In such a
case, the baselines ~2500 km (~1500 km) may be expected to lead to hierarchy
determination (\delta_{CP} discovery) with the minimum exposure.
