  Spin-orbit torque can drive electrical switching of magnetic layers. Here, we
report that at least for micrometer-sized samples there is no simple
correlation between the efficiency of dampinglike spin-orbit torque
({\xi}_DL^j) and the critical switching current density of perpendicularly
magnetized spin-current generator/ferromagnet heterostructures. We find that
the values of {\xi}_DL^j based on switching current densities can either under-
or over-estimated {\xi}_DL^j by up to tens of times in a domain-wall depinning
analysis, while in the macrospin analysis based on the switching current
density {\xi}_DL^j can be overestimated by up to thousands of times. When
comparing the relative strengths of {\xi}_DL^j of spin-current generators, the
critical switching current densities by themselves are a poor predictor.
