I like it so much I already made a similar suggestion.
But yes, I like it..
Specifically,
I woud like to see the following (simplify as needed):
For
positive:
Excellent teammate (or communicated well as teammate; gave us strategies to help us win; etc.
Helped me learn the map/game/etc.
Humorous chat
Put up with abuse from another player with good grace or defended well another player who was being abused.
Excellent game play/strategy
For
Negative:
Attacked wrong opponent in Assassin
Did not communicate with teammates
Ignored advice from other teammates, causing us to lose.
Does not speak English (note -- I include this mostly so those of us who would NOT care can seperate it out).
Missed 1 turn. (when CC server working fine)
Missed repeated turns for what I consider to be good reasons.
MIssed repeated turns for no reason, for strategy or poor reasons.
Deadbeat, without reason or I don't accept reason.
Deadbeat, but offered reason or gave us warning.
Gave up/suicided before game was over.
Seemed to have unannounced alliance.
Violated terms of announced alliance.
Generally poor player.
Started speed game, but never played.
Deadbeat speed game.