Actually, thinking about this I have thought of another point.
Is your rating stored rounded off or just displayed rounded off? For example, if your rating is calculated and then rounded off before storing on the database, this can cause rounding errors. Would be better if it is stored at maybe 2 decimal places and what is displayed is rounded.
Although the latter point might be implemented already (which Russ obviously would know) and wouldn't be a problem.
Anyway, regardless, it is probably a pedantic point and not really worth worrying about. 🙂
Lau