The new generation XP and GG and v2 polishers offer dramatically more ability to keep a pad rotating and thus more ability to remove defects.
I feel like a broken record some days because I'll type the same thing over and over again but not only have i used the PC after it was first introduced, but I've taught a kazillion people first hand how to use it and one thing I always had to address was pad rotation and how as your pad became saturated with product that this would reduce the tools ability to keep the pad rotating and this means it will take you longer to remove the swirls, thus longer to detail the car.
The new generation polishers fix that problem. They really do a better job of keeping dry pads rotating and wet pads rotating and the longest part of ANY detail job that includes removing swirls and scratches is the cleaning step, that is the step where you're removing the defects out of the paint.
The old tools will do it, but they are not as effective and the will take longer. One around the deficiency of the first gen tools is to have plenty of dry pads on hand. When you see the pad's rotation slow down simply take the wet pad off and replace it With a dry pad and wa-la the pad will start rotating better again.
Pretty easy experiment to test yourself.