Illustrator - Comparison Between Drawn Image and Live Traced Image

Both of the images were created in Illustrator.

For the image on the left I imported my pencil sketch and then traced it using the Pen Tool.
I threw away my sketch when I gad finished tracing.

It's slow but very accurate.

For the image on the right I imported my sketch into Illustrator and Live Traced it.
That means that the computer created the line work for me.

It's faster, but not as accurate.