In general, GFE would be more kissing, cuddling, And chatting, and PSE would be more wall to wall fucking. Some folks will say GFE has to include Certain services like BBBJ, DFK, and DATY. And some say PSE should include anal (some even say PSE includes BBFS) I say it is more of the attutude and atmosphere vs actual acts.

The point is there is no real standard definition so the only way to know what to expect is to get VIP membership and read reviews.

I liked the term PERSONAL SLUT EXPERIENCE....

When I offered PSE What I included was Greek, fisting, deep throating, spitting on the cock,  HARD hair pulling, LOTS of nasty dirty talk.. The VIBE of the experience IMHO is different in PSE... Like you are ravaging each other, almost hate fucking.. it is fast, hard, deep, rough, intense, nasty, kinky, dirty...  

 
For me GFE is very passionate, sensual, softer, caresses, touches, eye contact, more body to body holding, kissing till you have to come up for air.. but at a slower pace, more gentle...