What was the point you were trying to make, again?
You said what did DJ improve other than AP? It increases his AP and the speed of his kicks; as stated in manga:
Why
are you quoting me, though? I think Sanji with DJ > Jyabura. I'm merely stating that before DJ, Sanji was obviously overwhelmed non-stop by Jyabura and had to resort to DJ to win. If you disagree, only talk about that lol