With X-Plane 920 RC1, the user can now control how smooth taxiway curves look. More smoothing looks better, but can slow frame-rate.
So authors: please use the minimum number of vertices to create a bezier curve. If the user wants it to look smooth, he or she can crank the rendering settings. If the user has the setting on "low" it's probably due to a lack of hardware.
Below are four pictures of KSBD (which has good, sparse vertices) at the four rendering settings.