I can't define PSE, but I know it when I've had it! Usually because I'm limping out of the apartment, seeing cross eyed and drooling uncontrollably! (And no! Before you cay it - nothing to do with alcohol!)
The specifics and services are irrelevant to the classification of a PSE for me. Its more to do with the intensity and the impression that the said lady is desperate for it. (All it the act of course).
GFE is more my thing, but I must say the couple of time I've had a PSE, its been mind blowing!
"Don't be reckless with other people’s hearts. Don't put up with people who are reckless with yours"