The benefits of an optimised Super-X divertor configuration in mitigating the steady-state power and particle fluxes to the surfaces of the MAST Upgrade divertor have been quantified by performing a detailed comparison with a conventional divertor for the first time.  In otherwise identical plasmas with conventional and Super-X divertor configurations in the attached regime, the divertor heat flux is reduced by a factor ~10 in the Super-X configuration due to a combination of geometrical expansion of the area over which power is deposited in the divertor and increased dissipation in the divertors.  The core density required to access the detached divertor regime was reduced by a factor 2 in the Super-X configuration, in good agreement with modelling predictions.  In the operating conditions studied here, there was no significant impact on the plasma core temperature and density profiles, and hence confinement, even when the conventional divertor is in the attached regime and the Super-X is detached, showing that confinement of the core plasma is preserved even in the presence of significant dissipation in the divertors.