User blog comment:Tsumou/Creating VOCALOID Music. Who is best to use?/@comment-53539-20140809233032

So long as you can understand Japanese enough to use these Vocaloids, there is actually quite a lot of options.

Avoid;
 * Akoi Lapis
 * V3 Lily
 * VY2 (VY1 has a slower tempo range)
 * Any of the KAITO V3 vocals is a "no, no", with the exception of "Whisper" which has #65BMP range
 * Zola Project
 * Hatsune Miku V3 English - 100bmp? Walk a mile around it!
 * Hatsune Miku V3 "original" and "Soft", any of the other 3 appends are fine, especially "sweet" as it was built for this, Miku's package is quite good overall to be fair with 3 "slow" vocals.
 * Macne Nana
 * Meiko V3 "Straight" and "English", Meiko, like Miku's package, is overall pretty good actually and has "3 vocals" that are slow as well. The only one who currently out does these two is Gumi.
 * Kanon, but not Anon out of anon & kanon
 * Flower
 * Tohoku Zunko
 * IA Rocks... 95 bmp? Though right now the only way to get the original IA vocal is to buy the duo package, meaning, you will end up with this vocal if you seek the original regardless.
 * Galaco - "Red", you want "blue" for the ballards, "red" doesn't cut it out.

Most of the Vocaloids are pretty good for ballads with the exception of the ones I've listed. You can still use Vocals on the list (the ones at 70 bmp can just get away with it, but anything 80 bmp or avoid isn't going to cut it). These vocal shave traits like "vividness" which makes them unsuitable, they end up with lack of smoothness, or turning up oddities in their samples, making warping noises, etc, etc.

The vocal with the least minimum bmp is Cul at 40 bmp right now, but Cul's bmp range is crazy large. O_O