Scores vary from one reviewer to another- sometimes a lot. If a girl has several low scores (5 or less) then I will most often not investigate further because this is an immediate indication that the girl has problems.
The first thing I do is to look at a girl's TER page and look at the information listed, particularly her physical attributes, what she does and doesn't do, her price, and then her scores, looking for 7 and better. Then I go to her site or ad and look at her photos, and if I like what I see, I read the most recent reviews, maybe 2-4 reviews, and then look at her worst scored reviews and look for any kind of pattern. If she is in my price range, has looks and attributes that appeal to me and her reviews are generally positive, then I add her to my favorites, and periodically review my favorites to see what might appeal to me to try on my next adventure.
Like a lot of guys here, I tend to ignore some lower scored reviews if:
1. The descriptions are positive and the reviewer just scored lower than others
2. The description is very different from the reviews of a group of guys who gave good reviews.
We all know that girls can have an off day, or they don't click with a guy, or the guy is being an A-hole to the girl for some reason that isn't obvious (such as not getting Greek when the girl doesn't do Greek, or BBBJ etc.) If I am still uncertain, I look at the reviews that I am unsure about to see the history of the reviewer, and if I know him, know his reviews and believe him to be reputable. I will also PM the reviewer to ask specific questions. That's one of the reasons why this is such a good place for guys to find out about girls and figure out of they want to see them.
Once I find someone that I want to see, the thing that will make me pull the trigger on seeing her is the reviews, not the scores.