I know I've given a couple 10's. But at the time I gave them I thought she was the hottest I had the chance to meet. Then later I get the opportunity to meet another that is just as good or better, so I have no choice but to give her a 10 also.
That being said, when i look at other's reviews, I always knock the average down a notch. So if she averages a 9, then i figure she'll be pretty hot, if she averages an 8, it's still promising, but no longer will I see an average below an 8, even if her looks really tempt me because I feel most people inflate their ratings (and weight scale also)