Which is stronger? Who would win?

I really have no idea which jutsu is the strongest, but seeing as it took 3 years for the fourth to learn it and ero-sennin is using it, i'd have to say i think that jutsu is stronger than the Chidori...

PS. Hang me if you want, but i've searched for this subject, i've looked through a lot of pages, used the search-function, so f*** off.