Before revision:  Numeric simulations indicate that the R-test is more powerful than Student's t-test for semi-heavy and heavy-tailed distributions, equivalent for Gaussian variables and slightly worse for uniformly distributed variables . Finally the R-test has a greater power than the single-sample Wilcoxon signed-rank test in most cases .
After revision:  Numeric simulations indicate that the R-test is more powerful than Student's t-test for semi-heavy and heavy-tailed distributions, equivalent for Gaussian variables and slightly worse for uniformly distributed variables , and more powerful than the sign and Wilcoxon signed-rank test in most cases .