PSLP is basically a leadership development programme, for those with Leadership Potential (formerly CEP) of at least a MX 7 (DS). There are different 'types' of PSLP's by profession, i.e. social services, comms etc, however, I don't know what's the difference in end goal. Those on PSLP are given an allowance (the higher your current grade, the higher allowance), on top of their annual salary. This is paid out in two tranches every half a year. In return, you may be given additional projects on top of your current work. Your career will also be tracked more closely the service. As for how fast you move, it is also dependent on your performance.