[en] Long-pulse spallation sources will offer a very high time-integrated neutron flux similar to that of the best steady-state sources. Using Monte Carlo simulations we show that the exceptional source qualities translate directly into strongly enhanced instrument performance for a large class of instruments ranging from high-resolution backscattering to low-resolution small-angle scattering. The relation of the source duty cycle to the required wavelength resolution of the instrument is in this context a crucial performance indicator. Very large additional gains are achievable by properly tailoring the instrument parameters to the source characteristics and by fully exploiting modern neutron optics. In all cases investigated the long-pulse structure can be turned into an asset for the instrument design by using the known concepts of pulse shaping and frame multiplication