My experience is with UberX but I would say tipsy equals higher ratings where as when you get later in the night and the people are ridiculous drunk and there is surge pricing going on they either aren't coherent enough to rate rationally or they are taking their anger at the higher costs out on the driver.

it was only one night... so my data points are minimal compared to yours... you may be right (or you may be a better driver!) :)

John I a curious did you inform your insurance carrier what commercial activity you were participating in before you started?