In general, the specific acts offered/allowed by a GFE and PSE provider may not vary that much. Many GFEs offer Greek tours, or CIM, for example.

I have had two recent experiences which I would term GFE and PSE.

The GFE session she was up for most anything (no Greek), but while the session was hot and steamy, there were breaks in-between to chat, etc. Also, there was BBBJTC-interruptus during a HOT 69 where she just need to stop what she was doing to focus on her experience.

My recent PSE session was with two gals I have seen a few times. It was not PSE becuase it was a truly Bi duo session. It is PSE because from the second I step out of the shower it is non-stop mouths, tongues, fingers, etc. until I hop back into the shower. These ladies feel they haven't done their job if I don't drop three cups in an hour, which is insane.

Some will try to define GFE/PSE by services/acts (Greek, CIM, NQNS, etc.), but there is also the pace/attitude side as well.

A third aspect is having to do every possible position imaginable during the session. To me this wouldn't be fun. I'm into what I call the NGFE - Naughty GFE. It's something between a slow & sensual GFE, and the crazy non-stop PSE.