Burst of Speed (Ex)
At 3rd level, a dervish takes only a –1 penalty to her AC after charging. At 7th level, the dervish can charge with no penalty.
This ability replaces Armor Training 1.
How does this interact with feats and abilities that increase the AC penalty of charging, such as a Savage Warrior's Savage Charge, or the Sliding Dash feat? Would it completely remove the penalty, or only reduce it by two, or should it be ruled to reduce it by 1 + 1 for every four levels past 3rd?
I suppose the same could be asked of the Nimble Striker feat as well.