The 1ZPI has two stages. The initial aggressive cut doesn't last long, so it's better to utilize it. Start slowly, around 800 RPMs and spread a film over the working area. Work the polish in with some pressure. When it starts to break down, increase the speed to 1000-1200 to break the abrasive down to an even finer state. Finally dial back the RPMs and refine the finish.
If you start too aggressively with too high RPMs the abrasives break down almost immediately and the PI won't be effective.
It is a perfect companion to high speed, short throw DAs (preferably over 11.000 OPMs). Start on speed 3, with a little pressure, and when it begins to break down, kick it to 6 and continue working. As it reaches its final state and goes translucent, lift the machine a bit to refine the finish. Usually it produces a very clear, almost LSP ready surface. If you spritz the residue with QD and continue working it, it becomes even finer.
Yes, totally different from SIP (I'm using 3.02). The Menz works better on harder paints, but it won't cut as aggressive as the 1Z.