kakashi said he could perform the raikiri like, 4 times (or was it 6 times).....a killing move is a killing move, no matter who its done by, so how strong it is isnt the issue...but kakashi can use it twice as many times as sasuke can in a day. (which is kinda weird how sasuke was able to go for a 3rd chidori stab into the rock in that ep...im guessing he has more chakra since he wasnt using his sharingan at the time)
and you dont KNOW if jiraiya is gonna teach naruto a new technique thats better than the chidori....it sounded to me like he was just saying that cause he knows it'll get naruto's attention (then again i only watched the raw of this ep, so maybe he mentioned it again and i didnt notice)