A review and recent progress are presented from experiments on masses and lifetimes of bare and few-electron exotic nuclei at GSI. Relativistic rare isotopes produced via projectile fragmentation and fission were separated in flight by the fragment separator FRS and injected into the storage ring ESR. This worldwide unique experimental method gives access to all fragments with half-lives down to the microsecond range. The great research potential is demonstrated by the discovery of new isotopes along with simultaneous mass and lifetime measurements. Single particle decay measurements and the continuous recording of both stored mother and daughter nuclei open up a new era for nuclear spectroscopy. The study of bare and few-electron nuclei has also important astrophysical relevance with respect to the hot stellar conditions where reactions and decay are influenced by the degree of atomic ionization. The future international NUSTAR facility at FAIR consisting of a new large-acceptance in-flight separator (Super-FRS) and a dedicated storage ring system (CR-RESR-NESR) will be an ideal tool to study nuclei with new probes and to investigate the majority of relevant r- and rp-process nuclei which are not in reach with the present-day facilities.