 The X52 uses only a single spring mounted vertically to keep it centered, while the X52 Pro uses dual springs for stronger centering.This enables quick direction changes on the stick without "clicking" through the axes - a problem common to other sticks which normally feature two springs mounted horizontally.The X52 also features an integrated mouse on the throttle, however it is difficult to use for making quick selections and only functions when drivers and the SST software are installed.