My perception could be slightly different on this topic. I don`t necessarily think PSE means the woman is aggressive and takes charge, but that she makes me feel like a porn star.
For example, once in a while when I am getting an awesome I get the urge hold on to the SP`s head and start taking control. If I am with someone advertised as GFE I might test the waters gently before committing to anything, with a PSE I feel much more confident to start some of the more aggressive stuff (like face fucking). As always, if the SP indicates her displeasure then it stops (goes without saying).
Also, even though there are several things I don`t seek like Greek or Rimming, the notion that this SP is a PSE and anything goes (as they are frequently advertized) creates a nice thrill and lets the imagination wander.