Is it better to sculpt with or without dynamic perspective? Why would you choose one over the other? Thank you.
If your question is whether it’s better to sculpt with perspective on or off, this is largely a matter of preference. Some people feel that working with perspective on gives a better approximation of the object’s true appearance in the world. However, you should always disable perspective if you are trying to line up exact proportions, say for a machine-perfect object–for instance if you need to make sure that two sides of something are exactly the same length. Perspective will distort this.
If your question is whether it’s better to to work with the dynamic mode in the perspective button on or off, it probably depends on the situation. Hold ctrl and mousover the perspective button. It will give you the official explanation of the mode. Evidently when active, Zbrush will auto adjust the camera to avoid clipping issues.