Check out the changes on the review interface of Google Plus Local Reviews using Zagat -aside from the content inputs. Poor, good, very good and excellent are obviously more understood than their numerical counterparts.
“Update: Google not only changed the output of the
review content but they changed the interface at the time of review creation to have users select from the descriptive phrases as well. See photo below. ”
Since keywords are used when searching for anything online, it makes sense that the descriptive terms will be more SEO-friendly than numbers!