[nye2k]

The greatest takeaway here is that, by using live action as reference for both character posing and timing, you're able to shortcut visual appeal.

Read The Illusion of Life, Animators Survival Kit and the Preston Blair book if you're serious about including animation in a project -- or befriend an animator. Animators don't let other animators rotoscope.

[cpfohl]

I'm not sure I'd go as far as that. Rotoscoping creates a unique visual style, I like the look.

Want to elaborate?

[searine]

To make animation appealing you need to anticipate, exaggerate, and squash/stretch motion.

These do not appear on rotoscoped footage because they do not occur in real life. If you rely on rotoscoping the result is bland movements which lack a "spark of life".

In other words, rotoscoping creates an "uncanny valley" for motion.

[TrevorJ]

Even Disney rotoscoped. Tools are tools. They are all useful, the secret sauce is knowing when and where it's appropriate to employ them.

[nye2k]

Disney has used live action as a tool from early on, you can see this plain as day in Snow White's dancing scenes from 1937 because the movement feel awkward. And this is from animators with classical training who knew where the line needed to land on every frame.

Rotoscoping, tracing back each frame, is more what you will find in A-Ha's Take On Me music video, or Ralph Bakshi's film Fire and Ice. It is limited with poor line quality, and used primarily because the labor is cheap.