The scoring system on SOL gets lots of discussion. I sympathize with Lazeez; setting up any system is tough. Readers tend to only score stories they like, and I suspect, despite those who "1-bomb," there's a tendency to be nice to an author who has just given you perhaps many hours of enjoyment. So what if it wasn't at the very peak - give it a 10! This all leaves a set of scores that skew really high and leave readers trying to decipher the significance of tenths of a decimal point. (Much the situation on that dominant e-book site!) All, in all, from a reader's viewpoint only, I think he's done a pretty good job, although I'm not sure just how much to discount the pre-2013 scores.
Anyway, when you score a story, how do you do it? Do you start at 10 and take off for things that matter to you? Have you read enough on SOL (or do you use a bigger base?) to have a sense of what a "6" is and go from there? Me, I tend to start at somewhere around a 7.5 as I figure I'm only picking stories I already think are going to interest me and that have signs they are well-written (blurb, author's blog, maybe the first chapter or other stories by the author). Then I go up or down, depending. Page-turning engagement (narrative drive) and emotional impact probably influence me more than anything.
How do you score? And do you find the scoring system helpful as a reader?