The biggest complaint maybe has been the choice to use a English song as the "main" song.
Miku even appeared on Letterman before her event for some plugging. It was truly a television first to have a software as the musical guest.
The official Hatsune Miku youtube channel has uploaded a short clip from the NYC show. You can see a bit of Sharing the World and the World is mine.
Now the question is when can we finally get Hatsune Miku to Europe.