Well, Riddaren, I don't even mind cavalry. I think it's easy to be effective as one (lancer, mind you) by playing in a boring manner, however a person completely new to the game would be better of stacking strength with a long polearm/two-hander than going archer/cavalry.
I just think most average or good players can easily match their scores at their best class as a lancer without having to do as much work. It's just the nature of the class, and no, I don't think it's op. You pay upkeep for an advantage and that's the ability to choose your battles and flee from bad positions at any given time. Speed bonus is a double-edged sword so I won't necessarily say that one of the advantages is great damage, because it's very situational.