How does it feel when PSM engages?

[986 Boxster]

In my experiences the PSM on, it did reduce power to the car and it also braked the car when it engaged, and the psm light will come on momentarily on the cluster. I've had it come on several times on turns that the back end started to slide and it did brake and the car slowed down also with power being reduced, It didn't feel the same as the abs coming on. It will come on also when you try to spin the rear wheels. When I turn it off, it doesn't do anything to the car when I try to spin the wheels and I can slide the back end of the car if I want.