Lephurn does have a point though, you could get a nice session once and vote +1 but if you go back and the session is mehh for whatever reason, then you shouldn't vote -1 because you've voted once for the same MA? All sessions may vary and regardless if it's the same client, it should be counted. I thought the essence of the voting was to 'reward' the MA's who consistently provide a good session, whoever benefits from it. Just my 2 cents on that.
FYI, i've actually only seen one but you're right...i should fess up, water under the bridge.