Worth its SALT: four years of full science operations with the Southern African Large Telescope

SALT is a 10-m class optical telescope located in Sutherland, South Africa. We present an update on all observatory performance metrics since the start of full science operations in late 2011, as well as key statistics describing the science efficiency and output of SALT, including the completion fractions of observations per priority class, and analysis of the more than 140 refereed papers to date. After addressing technical challenges and streamlining operations, these first years of full operations at SALT have seen good and consistently increasing rates of completion of high priority observations and, in particular, very cost-effective production of science publications.