As an example: Effects > Distort & Transform > Free Distort which has a dialogue box where you manipulate the effect but, the preview doesn't show the graphic within the context of your design (attached sample). Because some controls like Free Distort don't have a slider, or mathematical value we can assign, it's very challenging to manipulate the graphic with any contextual accuracy. For this particular effect, and others that have a similar user experience, if there was a live Preview, or a window showing it in context of it's area of the artboard, it would minimize the nudging/adjusting/clicking that has to be done to dial in the accuracy of the effect.