In some cases this may take more time than the geodesic buffer created using the Planar option, but the result is a buffer that more accurately matches the shape of the input feature. If you are concerned about the shape of your buffers and how closely their shape matches the original input features, it is recommended you investigate using this option, particularly when your input data is in a geographic coordinate system. The shape-preserving geodesic buffer densifies the input features prior to creating the output geodesic buffers in order to create buffers that more closely represent the input features shape.