There's nothing wrong with assert, that's what I use for checking conditions as well. The framework posted is just a thin facade on top of regular functions and asserts to provide fixtures, dynamic grouping and benchmarks. Knowing how long a specific set of tests take to run for N repetitions is useful information. Since I wrote the test, I know exactly how many times the tested API is called. This is about spotting problems and trends early, once I find something interesting I'll drop down to profiling.