JC if you're in a turn fight in a 109, you need to use more rudder and only 1 or 2 notches of flaps, any more and thats when you snap-roll! the 190 is even worse! when im turning to the left, i use alot of rudder to keep the nose up it works well, but you have to stay on top of it, and almost predict what its gonna do, once you lose it, it will roll right over on you. if you turn to the right, you're fighting torque and the turn is slow, and you will die! its manageable as far as turning goes, but you cant keep up in a turn fight. always turn to the left in a 109 if you can. i hope this helps.
just my opinion, your mileage may vary!