I think the Object Test Bench would be best suited to drop-in components, such as those designed to be reusable.
There is an ideal that some programmers strive for, sometimes referred to as an "orthogonal" style or model. Essentially, the point is to reduce coupling and interdependence. Generalize classes or narrow their scope and they become more re-usable and easier to modify without things blowing up. In terms of the Object Test Bench, if you code with an orthogonal style, it would certainly be easier to test your components independently.