I agree with this so much. It's really not very intuitive and it's just kinda clunky. (Though, what do I know? I haven't used Vocaloid in ages; I just use Piapro! )Opinion: I think the Vocaloid editor has one of the weaker interfaces of any vocal synth on the market. A lot of the tuning process ends up being left to guesswork. I can't wait for CeVIO and SynthV to release more vocals, because I adore their interfaces!
Also, opinion: UTAU tuning > Vocaloid because I can actually pitchbend exactly the way I want instead of guessing how to draw the damn pitchbend and hoping that it works. I wish more synths used that method; it's so much easier and efficient (at least with the Pitch Editor plugin anyways).
I think more synths need to allow third-party plugins; it benefits UTAU so much that I basically rely on them to get anything done.