Slightly off your point but another major advantage of Nico over YT is that the videos will still be there 3 months down the road since there won't be any copyright claims.
YT does seem to go way to far in copyright enforcement and lets face the reporting system is way too easily abused as in anyone can flag your video.
Your best defense is to put a little fair use legalese in the description.
Nico is generally a lot less likely to go after copyright issues then youtube the same goes for metacafe and vimeo.
Oh there's an English Nico site now.
Though I still have not figured out how to make it work on android and iOS yet.