Without the context of how the reviewer rates other movies, it's not possible to say whether 7 is high or low. I would say 7 is mid or mediocre, something I wouldn't go out of my way to watch. The trend I've noticed is that most people only use the top half of the scale, anything 5 and less is bad. The funny thing, and I am guilty of this myself, is when they only use 6 through 10 but then use decimal points too.