Okay, I've crunched the numbers by category for SPs I've seen:
Face/Body:
Fails to meet expectations: 27% of the time
Meets expectations: 46% of the time
Exceeds expectations: 27% of the time
Note: Those not meeting expectations in this category weren't necessarily unattractive facially, as the plainest looking SP I've seen was an acceptable 6/10. Girls who bomb in this category usually do so more for body issues (i.e. too many tattoos, over tanning, large ass, etc.).
Service:
Fails to meet expectations: 18% of the time
Meets expectations: 63% of the time
Exceeds expectations: 18% of the time
Note: Those failing to meet expectations typically either give an uninspired BJ or are too passive during FS.
Personality:
Fails to meet expectations: 36% of the time
Meets expectations: 45% of the time
Exceeds expectations: 18% of the time
Note: Girls have the toughest time pleasing me in this category. Those failing to meet expectations are normally polite and respectful but are simply out-to-lunch (i.e. immature, distant, dumb, guarded, superficial, insincere, under the influence, etc.). These girls usually can't carry on a decent conversation and/or are overly professional.
Percentage of SPs exceeding expectations in all three categories: 9%