Multi-Reflection Time-of-Flight Mass Spectrometry (MR-ToF MS) is a technique that hasrecently been introduced to nuclear physics research. The method is reviewed and several examples from ISOLTRAP at ISOLDE/CERN are given that illustrate its power and usefulness. Initially built for fast separation of the ions of interest from abundant contaminations in order to allow precision mass spectrometry, which was demonstrated in the case of 82 Zn, ISOLTRAP's multi-reflection time-of-flight mass spectrometer also succeeded in measuring the previously unknown mass values of 53 Ca and 54 Ca. In addition, proof-of-principle experiments have been performed which demonstrate further applications where fast and high-resolution separation of ions of interest from mixtures with high abundances of contamination species is required. Furthermore, in an off-line setup MR-ToF MS is explored with respect to space-charge effects in order to find the limits of the ion abundances that can be handled. The phenomena observed include peak coalescence in the time-of-flight spectra and different distributions of the kinetic energies of the stored ion species.