>>5696314in comparison,
https://www.youtube.com/watch?v=4hNpxi0N-2U was released before your first link and could be mistaken for a human.
you could argue individual examples all day, I think, but it always comes down to singer and song choice. if you choose a vocaloid that doesn't fit the song, or don't know what you're doing, of course it's going to sound shit, and vice versa.
