What exactly are you referring to? EAP works far better than 5% of the time or are you referring to a specific feature? I have V9 EAP (no Nav on AP for me yet) but all the current features of EAP that I have work 99% of the time for me.
EAP is Nav on AP. The rest of the other stuff (lane keeping/adaptive cruise control) is just regular AP from AP1.
Based on aggregate reviews of Nav on AP it bare works 5% of the time.