We report a thorough, rigorous benchmark of the TIP3P, OPC, and OPC3 water models with the popular general Amber force field for small molecules. Due to a limitation on the computational resources available to us, we present results based on fairly limited sampling -for every ligand, the HFE estimate is based on 5.25 ns of production dynamics (21 windows x 0.25 ns of sampling per window). Admittedly, this is not sufficient in duration for our automated pipeline to achieve convergence for every ligand. However, as we compare different water models under identical conditions, we can still make fair and valid comparisons and draw meaningful, useful conclusions. In SI Fig. , we plot the distributions of the A_c convergence metric from the simulations using the TIP3P, OPC, and OPC3 water models.