<p>The superiority of an obviously strategy-proof (OSP) mechanism relative to its direct revelation form is largely justified on experimental results between the English auction and the strategically equivalent second-price auction. We examine this result in a very different environment, uniform rationing problems, where OSP mechanisms have only recently been devised. In contrast to previous experimental evidence, we find similar performance between the direct revelation uniform mechanism and its OSP counterpart. Two other mechanisms that alleviate strategic uncertainty in different ways fare better. A strategically equivalent mechanism that provides non-binding feedback during the reporting period greatly improves performance. A sequential revelation mechanism produces modest improvements despite not possessing dominant strategies. We characterize each alternative to the direct mechanism, finding general lessons about the advantages of real-time feedback and sequentiality of play, as well as the potential shortcomings of OSP mechanisms.</p>