I've always wondered about this also Fester,
All the forces the rudder needs to counteract appear to be modeled, but I can't help thinking they are reduced some what along with the force the rudder itself can produce. Certainly the amount of side slip I can generate with the rudder seems quite small to me (a very subjective comment I know, I freely admit to having never flown any of the aircraft currently modeled in Aces High).
I've always put this down to the fact that not everyone here has a set of rudders (How many do? 20%, 30%, 40%?), and this is just one of those aspects of the game that is adjusted for game play over realism.
Any comment HiTech?